Patent Publication Number: US-10773138-B2

Title: Ball bat including a fiber composite barrel having an accelerated break-in fuse region

Description:
FIELD OF THE INVENTION 
     The present invention relates to a ball bat including a fiber composite barrel portion having an accelerated break-in (ABI) fuse region. 
     BACKGROUND OF THE INVENTION 
     Baseball and softball organizations periodically publish and update equipment standards and/or requirements including performance limitations for ball bats. One recently issued standard is the Bat-Ball Coefficient of Restitution (“BBCOR”) Standard adopted by the National Collegiate Athletic Association (“NCAA”) on May 21, 2009. The BBCOR Standard, which became effective on Jan. 1, 2011 for NCAA baseball, is a principal part of the NCAA&#39;s effort, using available scientific data, to maintain as nearly as possible wood-like baseball bat performance in non-wood baseball bats. Although wood ball bats provide many beneficial features, they are prone to failure, and because wooden ball bats are typically solid (not hollow), wooden bats can be too heavy for younger players even at reduced bat lengths. Wood ball bats also provide little or no flexibility in the design of the hitting or barrel region of the bat. Non-wood bats, such as bats formed of aluminum, other alloys, composite fiber materials, thermoplastic materials and combinations thereof, allow for performance of the bat to be more readily tuned or adjusted throughout or along the hitting or barrel portion. Such characteristics enable non-wood bats to provide more consistent performance, increased reliability and increased durability than wood bats. 
     Other organizations have also adopted the BBCOR Standard. For example, the National Federation of State High School Associations (NFHS) has set Jan. 1, 2012 as the effective date for implementation of the BBCOR Standard for high school play. The BBCOR Standard includes a 0.500 BBCOR bat performance limit, which specifies that no point on the barrel or hitting portion of a bat can exceed the 0.500 BBCOR bat performance limit. 
     Another recent example of new bat performance limitations is the new USA Baseball bat standard (USABat) which also includes accelerated break-in testing of composite ball bats to ensure that the bat&#39;s performance does not increase during or after undergoing a bat rolling procedure. Effective on Jan. 1, 2018, Little League Baseball® will adhere to the new USABat standard, and no bats previously approved for use in Little League play will be permitted to be used in any Little League game or practice, or other Little League event. Other organizations implementing the new USABat standard include PONY Baseball, Babe Ruth Baseball/Cal Ripken Baseball, Dixie Youth Baseball, American Amateur Baseball Congress and Amateur Athletic Union. 
     When fiber composite bat barrels are used in a bat design, many of the new equipment standards and/or requirements also require the bat to undergo an accelerated break-in test procedure wherein the bat is repeatedly rolled in a barrel rolling procedure and then performance tested until the bat fails or shows evidence of failing. 
     Accordingly, a need exists to develop a method and/or system for forming barrel portions of a ball bat or other cylindrical portions of a ball bat using fiber composite material that can satisfy ball bat equipment standards and/or requirements in a cost effective, reliable and high quality manner. What is needed is a system or process of developing a ball bat that provides a high quality cosmetic appearance, is highly durable, and provides the desired operational characteristics. It would be advantageous to provide a ball bat, and a system or method for producing a ball bat including a barrel portion formed of fiber composite material, that can satisfy performance requirements, such as BBCOR certification or the USABat standard, without adding too much weight or wall thickness to the barrel portion. It would be advantageous to provide a ball bat with a desirable level of barrel stiffness, and provides exceptional feel and performance. 
     SUMMARY OF THE INVENTION 
     The present invention provides a ball bat extending about a longitudinal axis and that is configured for testing under an accelerated break-in test. The bat includes a barrel portion including a proximal region and a distal region. The barrel portion is formed of a fiber composite material having wall thickness of at least 0.100 inch. The fiber composite material includes at least first and second plies. The first ply includes a first plurality of fibers aligned adjacent to one another and a first resin, and the second ply includes a second plurality of fibers aligned adjacent to one another and a second resin. The first ply includes a first fiber discontinuity and the second ply includes a second fiber discontinuity. The first and second fiber discontinuities are generally aligned with each other such that one of the first and second fiber discontinuities substantially overlies the other of the first and second fiber discontinuities creating an ABI fuse region of the barrel portion. The ABI fuse region forms a crack initiation location when the bat is subjected to the accelerated break-in test. 
     According to a principal aspect of a preferred form of the invention, a ball bat extending about a longitudinal axis and that is configured for testing under an accelerated break-in test. The bat includes a barrel portion that includes an inner surface and is formed of a fiber composite material having wall thickness of at least 0.100 inch. The fiber composite material includes at least first and second plies. The first ply includes a first plurality of fibers aligned adjacent to one another and a first resin, and the second ply includes a second plurality of fibers aligned adjacent to one another and a second resin. The inner surface of the barrel portion defines at least one annular groove. The at least one annular groove creates an ABI fuse region of the barrel portion. The ABI fuse region forms a crack initiation location when the bat is subjected to the accelerated break-in test. 
     This invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings described herein below, and wherein like reference numerals refer to like parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a ball bat in accordance with one implementation of the present invention. 
         FIG. 2  is a side perspective view of a barrel portion of the ball bat of  FIG. 1  including a sectional view of the wall of the barrel portion. 
         FIG. 3A  is an enlarged view of a section of the wall of the barrel portion of the ball bat taken at circle  3  of  FIG. 2 . 
         FIGS. 3B through 3E  are enlarged views of a section of a wall of a barrel portion of a ball bat taken at circle  3  of  FIG. 2  in accordance with other example implementations of the present invention. 
         FIGS. 4A through 4C  are side views illustrating example implementations of a plurality of layers of fiber composite material prior to wrapping around a bladder and mandrel in accordance with other implementations of the present invention. 
         FIG. 5A  is a top perspective view of a portion of two representative plies of fiber composite material spaced apart from each other in accordance with another example implementation of the present invention. 
         FIG. 5B  is a top perspective view of a portion of two representative plies of fiber composite material spaced apart from each other in accordance with another example implementation of the present invention. 
         FIG. 6  is an enlarged sectional view of six outer plies of a fiber composite material of a primary tubular region of a barrel portion. 
         FIG. 7  is a representation of a bat rolling procedure on a ball bat and is a reproduction of  FIG. 1  of the NCAA Standard for Testing Baseball Bat Performance, Bat-Ball Coefficient of Restitution. 
         FIG. 8  is a side view of a ball bat in accordance with another implementation of the present invention. 
         FIG. 9  is a side view of a ball bat in accordance with another implementation of the present invention. 
         FIG. 10A  is a top, side perspective view of an annular stiffening element in accordance with an example implementation of the present invention. 
         FIG. 10B  is a cross-sectional view of the annular stiffening element of  FIG. 10A . 
         FIGS. 10C and 10D  are cross-sectional views of annular stiffening elements in accordance with other example embodiments of the present invention. 
         FIG. 10E  is a cross-sectional view of a polygonal shaped stiffening element and a barrel portion of a bat in accordance with another example implementation of the present invention. 
         FIG. 11A  is a top, side perspective view of a disc stiffening element in accordance with an example implementation of the present invention. 
         FIG. 11B  is a side perspective view of a disc stiffening element in accordance with another example implementation of the present invention. 
         FIG. 11C  is a top, side perspective view of a disc stiffening element in accordance with another example implementation of the present invention. 
         FIGS. 11D through 11F  are top, side perspective views of disc stiffening elements in accordance with other example implementations of the present invention. 
         FIG. 12  is a longitudinal cross-sectional view of a portion of a bat barrel including an annular stiffening element in accordance with an example implementation of the present invention. 
         FIGS. 13A and 13B  are longitudinal cross-sectional views of portions of bat barrels including disc stiffening elements in accordance with other example implementations of the present invention. 
         FIGS. 14A  and B are longitudinal cross-sectional views of portions of bat barrels including disc stiffening elements in accordance with other example implementations of the present invention. 
         FIG. 15  is a longitudinal cross-sectional view of a barrel portion of a bat including an example ABI fuse region in accordance with an example implementation of the present invention. 
         FIG. 16  is a longitudinal cross-sectional view of a portion of a bat barrel including an ABI fuse region in accordance with another example implementation of the present invention. 
         FIGS. 17 through 21B  are longitudinal cross-sectional views of portions of bat barrels including ABI fuse regions in accordance with other example implementations of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a ball bat is generally indicated at  10 . The ball bat  10  of  FIG. 1  is configured as a baseball bat; however, the invention can also be formed as a slow pitch softball bat, a fastpitch softball bat, a rubber ball bat, or other form of ball bat. The bat  10  includes a frame  12  extending along a longitudinal axis  14 . The tubular frame  12  can be sized to meet the needs of a specific player, a specific application, or any other related need. The frame  12  can be sized in a variety of different weights, lengths and diameters to meet such needs. For example, the weight of the frame  12  can be formed within the range of 15 ounces to 36 ounces, the length of the frame can be formed within the range of 24 to 36 inches, and the maximum diameter of the barrel portion  18  can range from 1.5 to 3.5 inches. 
     The frame  12  has a relatively small diameter handle portion  16 , a relatively larger diameter barrel portion  18  (also referred as a hitting or impact portion), and an intermediate tapered region  20 . The intermediate tapered region  20  can be formed by the handle portion  16 , the barrel portion  18  or a combination thereof. In one preferred embodiment, the handle and barrel portions  16  and  18  of the frame  12  can be formed as separate structures, which are connected or coupled together. This multi-piece frame construction enables the handle portion  16  to be formed of one material, and the barrel portion  18  to be formed of a second, different material (or two or more different materials). In other implementations, such as shown in  FIG. 8 , the bat can be formed with a one-piece frame in which the handle portion, the intermediate tapered region and the barrel portion are one integral piece and the portions cannot be separated without destroying the frame. 
     Referring to  FIG. 1 , the handle portion  16  is an elongate structure having a proximal end region  22  and a distal end region  24 , which extends along, and diverges outwardly from, the axis  14  to form a substantially frusto-conical shape for connecting or coupling to the barrel portion  18 . Preferably, the handle portion  16  is sized for gripping by the user and includes a grip  26 , which is wrapped around and extends longitudinally along the handle portion  16 , and a knob  28  connected to the proximal end  22  of the handle portion  16 . The handle portion  16  is formed of a strong, generally flexible, lightweight material, preferably a fiber composite material. Alternatively, the handle portion  16  can be formed of other materials such as an aluminum alloy, a titanium alloy, steel, other alloys, a thermoplastic material, a thermoset material, wood or combinations thereof. 
     Referring to  FIGS. 1 and 2 , the barrel portion  18  of the frame  12  is “tubular,” “generally tubular,” or “substantially tubular,” each of these terms is intended to encompass softball style bats having a substantially cylindrical impact (or “barrel”) portion as well as baseball style bats having barrel portions with generally frusto-conical characteristics in some locations. The barrel portion  18  extends along the axis  14  and has an inner surface  30 , an outer surface  40 , a distal end region  32 , a proximal end region  34 , and a central region  36  disposed between the distal and proximal end regions  32  and  34 . The proximal end region  34  converges toward the axis  14  in a direction toward the proximal end of the barrel portion  18  to form a frusto-conical shape that is complementary to the shape of the distal end region  24  of the handle portion  16 . The barrel portion  18  can be directly connected to the handle portion  16 . The connection can involve a portion, or substantially all, of the distal end region  24  or tapered region  20  of the handle portion  16  and the proximal end region  34  of the barrel portion  18 . In another implementation, the handle portion  16  can be a tubular body having a generally uniform diameter along its length and an intermediate member can be fixedly attached to the distal end region  24  for coupling the handle portion  16  to the barrel portion  18 . The intermediate member can be used to space apart and/or attach the handle portion  16  to the barrel portion  18 . The intermediate member can space apart all or a portion of the barrel portion  16  from the handle portion  16 , and it can be formed of an elastomeric material, an epoxy, an adhesive, a plastic or any conventional spacer material. The bat  10  further includes an end cap  38  attached to the distal end  32  of the barrel portion  18  to substantially enclose the distal end  32 . 
     The handle and barrel portions  16  and  18  can be coated and/or painted with one or more layers of paint, clear coat, inks, coatings, primers, and other conventional outer surface coatings. The outer surface  40  of the barrel portion  18  and/or the handle portion  16  can also include alpha numeric and/or graphical indicia  42  indicative of designs, trademarks, graphics, specifications, certifications, instructions, warnings and/or markings. Indicia  42  can be a trademark that is applied as a decal, as a screening or through other conventional means. 
     The barrel portion  18  includes a primary tubular ball impact region  44  that defines the region of the barrel portion  18  that is commonly or preferably used for impacting a ball during use. The ball impact region  44  includes the center of percussion (“COP”) of the ball bat  10 . The COP is typically identified in accordance with ASTM Standard F2219-09 , Standard Test Methods for Measuring High - Speed Bat Performance , published in September 2009. The COP is also known as the center of oscillation or the length of a simple pendulum with the same period as a physical pendulum as in a bat oscillating on a pivot. In one implementation, the ball impact region  44  includes the center of percussion and an area plus and minus three inches from the center of percussion. In other implementations, the ball impact region  44  can have other lengths with respect to the longitudinal axis  14 . The length of the ball impact region  44  is at least one inch, and can be positioned at any location along, or extend the entire length of, the barrel portion  18 . 
     The barrel portion  18  is preferably formed of strong, durable and resilient material, such as, a fiber composite material. In alternative preferred embodiments, the barrel portion  18  can be formed of one or more fiber composite materials in combination with one or more of an aluminum alloy, a titanium alloy, a scandium alloy, steel, other alloys, a thermoplastic material, a thermoset material, and/or wood. In one implementation, the barrel portion  18  can be formed of a fiber composite material having wall thickness of at least 0.060 inch. 
     Referring to  FIGS. 2, 3A, 4A, 5 and 6 , a fiber composite material is preferably used to form at least a portion of the barrel portion  18 . As used herein, the terms “composite material” or “fiber composite material” refer to a matrix or a series of plies  50  (also referred to as sheets or layers) of fiber bundles  52  impregnated (or permeated throughout) with a resin  54 . Referring to  FIGS. 4A, 5 and 6 , the fiber bundles  52  can be co-axially bundled and aligned in the plies  50 . 
     A single ply  50  typically includes hundreds or thousands of fiber bundles  52  that are initially arranged to extend coaxially and parallel with each other through the resin  54  that is initially uncured. Each of the fiber bundles  52  includes a plurality of fibers  56 . The fibers  56  are formed of a high tensile strength material such as carbon. Alternatively, the fibers can be formed of other materials such as, for example, glass, graphite, boron, basalt, carrot, Kevlar®, Spectra®, poly-para-phenylene-2, 6-benzobisoxazole (PBO), hemp and combinations thereof. In one set of preferred embodiments, the resin  54  is preferably a thermosetting resin such as epoxy or polyester resins. The resin  54  can be formed of the same material from one ply to another ply. Alternatively, each ply can use a different resin formulation. During heating and curing, the resin  54  can flow between plies  50  and within the fiber bundles  52 . The plies  50  preferably typically have a thickness within the range of 0.002 to 0.015 inch. In a particularly preferred embodiment, the ply  50  can have a thickness within the range of 0.005 to 0.006 in. In other alternative preferred embodiments, other thickness ranges can also be used. 
     The plies  50  are originally formed in flexible sheets or layers. In this configuration, the fibers  56  and the fiber bundles  52  are arranged and aligned such that the fibers  56  generally extend coaxially with respect to each other and are generally parallel to one another. As the ply  50  is wrapped or formed about a bladder  58  and mandrel, or other forming structure, the ply  50  is shaped to follow the form or follow the shape of the bladder  58  and mandrel. Accordingly, the fiber bundles  52  and fibers  56  also wrap around or follow the shape of the bladder  58  or other forming structure. In this formed position or state, the ply  50  is no longer in a flat sheet so the fiber bundles  52  and fibers  56  no longer follow or define generally parallel lines. Rather, the fiber bundles  52  and fibers  56  are adjacent to one another, and are curved or otherwise formed so that they follow substantially the same adjacent paths. For example, if a ply  50  is wrapped about the bladder  58 , the ply  50  can take a generally cylindrical or tubular shape and the fiber bundles  52  and fibers  56  can follow the same cylindrical path or define a helical path (depending upon their angle within the ply  50 ). The fibers  56  remain adjacent to one another, are aligned with each other and follow substantially similar paths that are essentially parallel (or even co-axial) for example, when viewed in a sectional view in a single plane or other small finite segment of the ply  50 . 
     The fibers  56  or fiber bundles  52  are preferably formed such that they extend along the ply  50  and form generally the same angle with respect to an axis, such as the axis  14 . The plies  50  are typically identified, at least in part, by the size and polarity of the angle defined by the fibers  56  or fiber bundles  52  with respect to an axis. Examples of such descriptions of the plies  50  can be fibers  56  or fiber bundles  52  defining a positive 30 degree angle, a negative 30 degree angle, a positive 45 degree angle, a negative 45 degree angle, a positive 60 degree angle, a negative 60 degree angle, a positive 70 degree angle, a negative 70 degree angle, a positive 80 degree angle, a negative 80 degree angle, a 90 degree angle (extending perpendicular to the axis  14 ), and a 0 degree angle (or extending parallel to the axis  14 ). Other positive or negative angles can also be used. Accordingly, in the present application, a single ply  50  refers to a single layer of fiber composite material in which the fiber bundles  52  extend in substantially the same direction with respect to a longitudinal axis along the single layer, such as plus or positive 45 degrees or minus or negative 60 degrees. 
     Fiber composite material used to form at least a portion of the handle or barrel portions  16  or  18  of the bat  10  typically includes numerous plies  50 . The number of plies  50  used to form a barrel portion  18  can be within the range of 3 to 60. In a preferred embodiment, the number of plies  50  used to form the barrel portion  18 , or a primary tubular region thereof, is at least 10 plies. In an alternative preferred embodiment, the number of plies  50  used to form the barrel portion  18 , or a primary tubular region thereof, is at least 20 plies. In other implementations, other numbers of plies can be used. 
     Referring to  FIG. 5 , fiber composite materials typically are formed or laid-up using pairs of plies  50  having fiber bundles  52  extending in opposite angular polarities. For example, a ply  50   a  formed of fiber bundles  52  and fibers  56  generally extending at a positive 45 degree angle (also referred to as a plus 45 degree ply) will be paired with a second ply  50   b  that is formed with fiber bundles  52  and fibers  56  generally extending at a negative 45 degree angle (also referred to as a negative 45 degree ply). This pattern typically extends throughout a fiber composite material. The alternating angular arrangement of the fiber bundles  52  and fibers  56  is important to achieving and maintaining the structural integrity of the component or structure being formed of the fiber composite material. The overlapped region of the two plies  50   a  and  50   b  can be essential for ensuring that, once cured, the fiber composite material has the desired strength, durability, toughness and/or reliability. The transition between alternating pairs of plies  50  can also support the structural integrity of the composite structure. For example, a series of six plies could include a pair of plus and minus 30 degree plies, followed by a pair of plus and minus 45 degree plies, followed by another pair of plus and minus 30 degree plies. The transition from the minus 30 degree ply to the adjacent plus 45 degree ply also provides added structural integrity to the fiber composite material because an overlapped region, such as region  60 , still exists from one ply to an adjacent ply. In other implementations, pairs of plies  50  having opposite polarities but differing fiber angles can be used. In still other implementations, two or more plies can be of the same polarity, such as disclosed by U.S. Pat. Nos. 8,858,373 and 8,852,037. 
     Handle and barrel portions  16  and  18  formed of fiber composite material can include several layers of plus and minus angular plies of different values, such as, for example, plus and minus 30 degree plies, plus and minus 45 degree plies, plus and minus 60 degree plies. One or more layers of 0 degree plies, or 90 degree plies can also be used. Referring to  FIG. 6 , the plies  50  may be separated at least partially by one or more scrims  66  or veils. The scrim  66  can be used to enable independent movement of the plies  50  above and below the scrim  66  during use after the barrel portion  18  is molded and cured. The scrim  66  can also be used to inhibit, stop or reduce resin flow from one ply  50  to another ply on the opposite side of the scrim  66 . 
     The composite material is typically wrapped about a mandrel that is covered by a bladder  58 , the bladder  58  and mandrel once wrapped with the desired number of plies  50  of fiber composite materials is placed into a mold, pressure is applied to the bladder, and the fiber composite material is molded and cured under heat and/or pressure to produce the barrel portion  18  and/or a primary tubular region thereof. While curing, the resin is configured to flow and fully disperse and impregnate the matrix of fiber bundles  52 . In alternative embodiments, one or more of the plies, sheet or layers of the composite material can be a braided or weaved sheets or layers. In other alternative preferred embodiments, the one or more plies or the entire fiber composite material can be a mixture of chopped and randomly dispersed fibers in a resin.  
     Referring to  FIG. 4A , one implementation of a lay-up of a barrel portion  18  of a bat  10  can be seen. Separate plies  50  are shown, each having separate fiber angles and polarities. The plies  50  are shown as generally flat two-dimensional sheets prior to being placed or wrapped about the bladder  58  positioned over a mandrel. The mandrel is formed in a shape that defines the inner volume of a tubular barrel portion upon the completion of the molding and curing. The bladder  58 , when placed in the mold, is pressurized to exert a force or pressure onto the plies  50  ensuring that the plies conform to the shape of the mold and achieve proper compaction, and the desired wall thickness, etc. For example, the bladder can be pressurized to 150 psi. In other molding operations, other pressure values can be used. The bladder  58  and mandrel can be formed of any material that maintains its shape and integrity during the curing process, such as a polyurethane bladder over a wooden mandrel. Once the bladder  58  is in position, the process of “laying up” the plies  50 , or layers, comprising the fiber composite material can be performed. The shape and overall size of the plies  50  can vary from one to another. Each ply can be sized to extend about all or a portion of the underlying bladder  58 /mandrel or the underlying ply  50 . Preferably, the ply  50  is sized to extend or wrap around the entire or full circumference of the bladder and about the axis  14 . A plurality of uncured plies  50  of fiber composite material can be wrapped or otherwise applied about the bladder  58 . 
     Once the lay-up of the desired number of plies  50  is completed, the bladder  58  and mandrel with the wrapped composite layers or plies are placed into a mold, the bladder is pressurized, the mold is heated to form (mold and cure) the barrel portion  18 . After curing, the bladder  58  and the mandrel can be removed from the inner surface of the barrel portion  18  through conventional means, such as, for example, extraction or heating. 
     In some applications, it is desirable to produce a barrel portion formed of fiber composite material having high angle fibers (fiber composite material having fiber angles of 45 degrees or greater). The use of high fiber angles for the production of unidirectional fiber composite components, including a barrel portion or cylindrical portions of a barrel portion, can be desirable because the stiffness of the barrel portion, or a primary tubular region thereof, can be greatly increased without adding to the weight or the wall thickness of the barrel portion. 
     Referring to  FIG. 4A , in one implementation a ply  70  represents the innermost ply  50  or layer applied to the bladder  58 , a ply  72  is positioned over ply  70 . In one preferred method of laying up the barrel portion  18 , the plies  70  and  72  can be initially laid over each other and then wrapped over about the barrel portion as a pair of plies having opposite polarities. In other preferred methods, a single ply or three or more plies can be applied or wrapped about the bladder/mandrel as a single ply layer or a triple or higher ply layer. Plies  74  through  84  illustrate one potential lay-up of layers to a bladder/mandrel. Each of the plies  74  through  84  includes fibers angled with respect to the longitudinal axis  14 . In the example implementation of  FIG. 4A , the plies  70  through  84  include fibers angled with respect to the longitudinal axis by +45 degrees, −45 degrees, +30 degrees, −30 degrees, +60 degrees, −60 degrees, +45 degrees and −45 degrees, respectively. However, in other implementations, other numbers of angled plies can be used in the lay-up, laminate or wall thickness of the molded barrel portion  18  or primary tubular region thereof. 
     As discussed in the Background, many existing and new equipment standards and/or requirements require bats that include a barrel formed of a composite material to undergo an accelerated break-in test procedure wherein the bat is repeatedly rolled in a barrel rolling procedure and then performance tested to measure the peak BBCOR of the bat until the bat fails or shows evidence of failing. One example is the NCAA&#39;s Bat-Ball Coefficient of Restitution (BBCOR) testing protocol, updated on Aug. 1, 2016, which requires the measurement of barrel compression in accordance with ASTM F2844 and then the rolling of the bat using a barrel rolling procedure. 
     The barrel rolling procedure requires a bat rolling apparatus that includes two wheels, a fixture for pressing the wheels into the bat barrel in increments up to 0.012 inch, and a device to roll the barrel. The wheels are formed of a durable material such as nylon and have a diameter within the range of 1.5 to 3.0 inches. Following rolling of the bat, the BBCOR is measured using a bat test procedure. The bat rolling and bat performance testing is continued until the bat fails or exhibits a decrease of BBCOR value by more than 0.018 from the maximum value. The barrel of the bat is placed into the fixture and marked with a 0 degree orientation as identified in ASTM F2844. As shown in  FIG. 7 , the rollers are brought into contact with the barrel. The rollers are then displaced approximately 0.050 in for the initial rolling. For subsequent rolling, the displacement is increased by up to 0.012 inch. The barrel is rolled to within 2.0 to 2.5 in of the endcap and past the taper (or area of no contact between the rollers and the bat). The bat is rolled approximately 10 times in each direction. The bat is then unloaded. The bat is then clocked (or rotated) 45 degrees about its longitudinal axis, and the bat rolling steps are repeated. The bat rolling is repeated again after clocking the bat to 90 degrees and 135 degrees from its original position. The barrel compression is then re-measured using ASTM F2844. The rollers are displaced and the bat rolling steps are repeated until the barrel compression from rolling decreases by 5 percent. 
     The 2018 USABat standard also requires performance of an accelerated break-in procedure including a bat rolling procedure. When performing ABI tests, in order for a bat with a composite barrel to pass the test, the composite barrel bats must either fail (break) at some point during the test or show evidence of failing, cracking or crack initiation (depending upon the particular bat standard). 
     The present invention includes bat configurations, bat constructions and bat manufacturing methods that result in a ball bat with a composite barrel that performs well and includes a predictable and engineered failure area or ABI fuse region. The ABI fuse region enables the bat with the composite barrel to pass applicable bat standards which include ABI testing requirements and also provide a region that indicates whether the bat has been tampered with (by a bat doctor or the like) or whether the bat has passed its useful life. 
     The present invention involves introducing a discontinuity in a location on the bat barrel which can cause or result in a catastrophic failure of the bat barrel when the barrel is subjected to the rolling portion of an ABI test. 
       FIG. 3A  illustrates one example implementation of a barrel portion  18  of a bat formed of fiber composite material that includes an ABI fuse region  90 . The ABI fuse region  90  relates to a bat composition and/or structure that enables the bat to perform during normal or intended use, but fail or show indications of failure when subjected to an accelerated break-in (ABI) test or procedure including a bat rolling procedure. Prior to laying up the composite plies  50  onto a bladder/mandrel  58  and then curing the laid-up or “stacked-up” structure, the individual plies  50  (or layers or flags) of composite material are cut or sliced into two pieces forming a cut or discontinuity  92  in the ply  50 . The cutting or slicing of the ply  50  creates a discontinuity in the fibers making up the ply  50 . The cut  92  or slice can be applied to one or more plies  50  in the stack-up, and the cuts  92  or slices are generally aligned with each other such that at least a portion of the cut  92  or slice of one ply  50  overlies the cut  92  or slice of a second ply or more plies. In one implementation the cuts  92  or slices aligned so that the cuts  92  overlie each other within a longitudinal discontinuity dimension, d, within the range of 0 to 0.1 inch. In other implementations, the longitudinal discontinuity dimension, d, can be within the range of 0 to 0.25 inch. 
     In the example embodiment of  FIG. 3A , a total of 16 plies  50  are illustrated in the barrel portion  18  or the wall thickness of the barrel portion  18 . The barrel portion  18  of  FIG. 3A  is shown in a final manufactured state after the composite plies have been laid up about the bladder/mandrel  58 , placed under heat and/or pressure and cured. During the composite molding and curing process, the viscosity of the resin decreases such that the resin  54  flows throughout the ply  50  and other adjacent plies  50 . Accordingly, the cuts  92  are made prior to wrapping, laying up and curing the plies  50 , once cured the cuts  92  are present in the fibers  52  but the resin  54  has flowed to fill the space or void created by the cuts  92 . The cuts  92  are shown in 6 separate plies  50  of an example stack up of 16 plies  50 . The outermost plies  50   a ,  50   b ,  50   c  and  50   d  each include a cut  92 . The next set of four plies  50   e ,  50   f ,  50   g  and  50   h  are formed without a cut or a discontinuity. The next two plies  50   i  and  50   j  include a cut  92 . The cuts  92  formed in plies  50   a ,  50   b ,  50   c ,  50   d ,  50   i  and  50   j  are all generally aligned with each other such that the cuts  92  or discontinuities substantially overlie each other within the longitudinal discontinuity dimension d. 
     Referring to  FIGS. 3B through 3E , other example implementations of cuts  92  placed into plies  50  of a laid-up structure forming the barrel portion  18  of the bat  10  are illustrated. The number of plies  50  that include cuts  92  can vary in the composite structure. The position and spacing of the cuts  92  in the composite structure and between the plies  50  can also vary. The size of the longitudinal discontinuity dimension, d, forming the ABI fuse region  90  can also vary. Still further, the angle of cuts  92  can be varied. In some implementations, the cuts  92  are substantially perpendicular to the longitudinal axis  14  of the bat  10 . In other implementations, the cuts  92  can be angled from 30 to 89 degrees from the longitudinal axis  14 .  FIG. 3B  illustrates the composite barrel portion  18  having 8 plies with cuts  92 , the 8 plies are stacked directly upon each other, and are positioned toward the inner surface  30  of the barrel portion  18 . The longitudinal discontinuity dimension d is less than 0.1 inch.  FIG. 3C  illustrates an example implementation where the cuts  92  are in 8 plies  50  that are arranged in spaced apart pairs of plies  50  throughout the lay-up of the barrel portion  18 . The longitudinal discontinuity dimension d is less than 0.025 inch.  FIG. 3D  illustrates another example implementation where the cuts  92  are in 7 plies  50  that are arranged in generally random order throughout the outer two thirds of the lay-up of the barrel portion  18 . The longitudinal discontinuity dimension d is less than 0.02 inch.  FIG. 3E  illustrates another example implementation where the cuts  92  are in the 7 outermost plies  50  of the barrel portion  18 . The cuts  92  are angled with respect to the longitudinal axis  14 . The longitudinal discontinuity dimension d is less than 0.25 inch. 
     Referring to  FIGS. 4A through 4C , other example implementations of the present invention are illustrated. In  FIGS. 4A through 4C , the plies  70  through  84  are specific examples of plies  50  shown in the order in which they are laid up onto the bladder/mandrel  58 . In  FIG. 4A , the cuts  92  are illustrated on four of the eight plies (plies  84 ,  82 ,  78  and  74 ). The plies  84 ,  82 ,  78  and  74  include cuts  92  that are made substantially perpendicular to the longitudinal axis  14  of the mandrel which corresponds to the longitudinal axis  14  of the bat.  FIG. 4B  illustrates an example implementation where the cuts  92  are angled with respect to the longitudinal axis  14  by approximately 75 degrees. Plies  72 ,  76 ,  80  and  84  include cuts  92 . 
       FIG. 4C  illustrates another example implementation, in which the four of the plies are formed of two flag segments and each flag segment can include a different fiber angle. For example, ply  80  can be formed by flag segments  80   a  and  80   b  which are arranged end to end to form a discontinuity or cut  92 . Flag segment  80   a  includes fibers generally extending at an angle of minus 60 degrees with respect to the longitudinal axis  14 , and flag segment  80   b  includes fibers generally extending at angle of plus 30 degrees with respect to the longitudinal axis  14 . In ply  80 , the discontinuity or cut  92  formed by the abutting of the two flag segments  80   a  and  80   b  and the difference in fiber angle from flag segment  80   a  and flag segment  80   b  further contributes to likelihood a crack initiation occurring at the ABI fuse region  90  during a barrel rolling test of an ABI procedure. Plies  74 ,  76  and  78  are also formed by a pair of flag segments  74   a  and  74   b ,  76   a  and  76   b , and  78   a  and  78   b . As shown, the angles of the fibers can vary from one flag segment to the next. 
     The barrel portion  18  including a proximal region  34  and a distal region  32 , and the barrel portion can be formed of a fiber composite material including at least first and second plies. The first ply can be ply  80  which can include the flag segment  80   a  (or first proximal ply portion) and the flag segment  80   b  (or first distal ply portion). The ABI fuse region  90  is the first fiber discontinuity that separates the flag segments  80   a  and  80   b . The first plurality of fibers of the flag segment  80   a  are generally aligned to define first proximal angle with respect to the longitudinal axis  14 , and the first plurality of fibers of the flag segment  80   b  are generally aligned to define first distal angle with respect to the longitudinal axis  14 . In one implementation, the first proximal angle and the first distal angle can vary by at least 10 degrees. In another implementation, the first proximal angle and the first distal angle can vary by at least 30 degrees. 
     Referring to  FIGS. 5A and 6 , in another example implementation of the present invention, the cut  92  can extend through only a portion of the ply  50  and/or only through a portion of the fiber bundles  52 . In  FIGS. 5A and 6 , ply  50  has a thickness t and the cut  92  has a cut depth, d c , that is approximately 75 percent of the size of the thickness t. In another implementation the depth of the cut d c  can be at least 50 percent of the thickness t of the ply  92 . In one implementation, the cut depth d c  is within the range of 33 to 100 percent of the ply thickness t. In another implementation, the cut depth d c  is within the range of 50 to 100 percent of the ply thickness t. 
     When the cut depth d c  is less than 100 percent of the ply thickness t, the ply  50  can be more readily positioned and handled during lay-up or stack-up of the composite structure, such as the barrel portion  18 . Because the cut  92  is formed before the plies  50  are cured, a cut  92  extending entirely through the ply  50  can make the ply more difficult to handle and/or work with. Accordingly, in some implementations, the cuts  92  are made at a cut depth that is less than the entire thickness of one or more plies  50 . Cuts  92  that do not extend entirely through the ply thickness t still serve to create a discontinuity that can form an ABI fuse region. 
     Referring to  FIG. 5B , another example implementation of a cut  92  or discontinuity is illustrated. The cut can also be formed as a plurality of spaced apart cut segments  92   a  that collectively represent the cut  92  in ply  50   a . The spaced apart cut segments  92   a  can extend entirely through the thickness t of the ply  50  or through a portion of the thickness t of the ply  50 , also referred to as the depth of the cut d c , as shown in  FIG. 5B . The length of each cut segment  92   a  can be varied. Additionally, the size of the distance between the cut segments  92   a  can also be varied. The spaced apart cut segments  92   a  have a similar effect of creating a discontinuity that can be used to form the ABI fuse region  90 . Adjacent plies, such as ply  50   b  can include a continuous cut  92 . In other implementations, the adjacent plies, such as ply  50   b , may also include spaced apart cut segments  92   a , or no cut  92 . 
       FIGS. 3A through 6 , illustrated example implementations of the present invention. However, other implementations are contemplated in the present invention. The number of plies  50  used to form the composite structure such as the barrel portion  18  can be varied. The angles of the fibers within the plies  50  can be varied from ply to ply from one lay-up to another. The number of cuts  92  in a lay-up or stack-up can be varied from one application to another. The type of cuts  92  (the angle, depth, and length—segmented or non-segmented) can be varied. The depth d c  of the cut  92  of a ply  92  can also be varied from one ply to another ply. The use of flag segments to produce a ply can be used in one or more of the layers of a lay-up or stack up. The fiber angle of the fibers in adjacent flag segments can also be varied. The size of the longitudinal discontinuity dimension d can also be varied. The present invention presents a significant number of different implementations of fibers, fibers angles, cuts, cut angle, cut sizes, cut depths, etc. that result in an almost infinite number of combinations available for producing an ABI fuse region in a ball bat. Through use of these various cuts and discontinuities, a bat can be designed and customized for any application. The present invention also enables a bat designer to produce a bat with an ABI fuse region that will produce reliable consistent results on the field and in certification or qualification testing. 
     Referring to  FIGS. 8 and 9 , in other implementations, a stiffening element  100  can be longitudinally positioned in barrel portion  18  of the bat  10  so as to be adjacent to the ABI fuse region  90  formed in the construction of the barrel portion  18 . The stiffening element  100  can take a variety of different forms, shapes, constructions, sizes, and/or materials. The stiffening element  100  serves to increase the compressive strength, or the displacement compression, of the bat  10  at the axial location of the stiffening element  100  and at regions directly adjacent to the stiffening element  100 . The effect of the stiffening element  100  on the stiffness of the barrel portion  18  of the bat  10  can be shown by performing a displacement compression test of softball and baseball bat barrels such as described in ASTM Std. No. F2844-11 with the stiffening element  100  installed and with the stiffening element  100  removed or absent from the bat barrel portion  18 . Using ASTM Std. No. F2844-11, or an equivalent test, a measure of the barrel compression BC of a bat can be determined using a barrel compression test apparatus such as shown in FIG. 1 of ASTM Std. No. F2844-11. 
     In  FIG. 8 , a bat  10  formed with a separate handle portion  16  and barrel portion  18  is shown with the stiffening element  100  longitudinally positioned adjacent the ABI fuse region  90  on the handle portion side of the ABI fuse region  90 . In  FIG. 9 , a bat  200  formed of a one piece, integral bat frame  212  is shown in which the handle portion  16  is continuously and integrally formed with a tapered region  20  and the barrel portion  18 . The term one piece, integral bat frame means that the handle portion  16  cannot be separated from the barrel portion  18  without destroying or damaging one or both of the handle portion  16  or the barrel portion  18 . The bat  200  includes a stiffening element  100  that is longitudinally positioned within the barrel portion  18  of the bat  200  so as to be closer to the end cap  38  or distal end of the bat  200 .  FIGS. 8 and 9  illustrate that the ABI fuse region  90  can be longitudinally positioned on either side of the stiffening element  100 . In other implementations, a bat can include two or more ABI fuse regions  90  positioned on either side of a stiffening element  100 , or two or more stiffening elements  100  positioned on either side of an ABI fuse region  90 . 
     In one implementation, the stiffening element  100  is longitudinally spaced apart from the ABI fuse region  90  by a distance within the range of 0.1 to 1.0 inch. In other implementations, the stiffening element  100  is longitudinally spaced apart from the ABI fuse region  90  by a distance within the range of 0.2 to 0.75 inch. In other implementations, the stiffening element  100  can be longitudinally spaced apart from the ABI fuse region  90  by other distances outside of these ranges. If an ABI fuse region  90  is placed on either side of the stiffening element  100 , the distance from the stiffening element  100  to each of the ABI fuse regions can be the same or can be varied. 
     The placement of the stiffening element  100  adjacent to the ABI fuse region  90  creates additional stress or loads upon the ABI fuse region  90  such that when the bat is subjected to an accelerated break-in test the differential in barrel compression between the barrel portion  18  at the stiffening element  100  and the barrel compression of the barrel portion at the ABI fuse region facilitates failure or cracking of the barrel portion  18  at the ABI fuse region  90 . The barrel compression of the barrel portion  18  at the ABI fuse region  90  is lower than the barrel compression of the barrel portion  18  at the location of the stiffening element  100  which accentuates or increases the stress placed upon the barrel portion at or near the ABI fuse region  90  during the performance of an ABI break-in test. The stiffening element  100  creates a sudden change in barrel stiffness that can force a failure or catastrophic failure of the bat barrel portion  18  during the bat rolling procedure of the ABI break-in test. 
     The stiffening element  100  can be any structure that stiffens the barrel portion  18  and increases the barrel compression value of the barrel portion  18  at the location of the stiffening element  100 . The stiffening element  100  can be integrally formed with the barrel portion as shown in  FIG. 14 , or can be a separate component that is positioned within the barrel portion  18 . Accordingly, the stiffening element  100  can be molded and cured with the barrel portion, it can be co-molded with the barrel portion, it can be press-fit within the barrel portion, it can be attached to the barrel portion using an adhesive, it can be coupled to the barrel portion through an intermediate layer, or coupled in other manners, or in any combination of the above-mentioned manners. The stiffening element  100  can be an annular member that includes one or more central openings (such as  FIG. 10 a   ) or it can be a disc member (such as  FIG. 11A ) that provides a substantially uniform structure across the hollow barrel portion  18 . In another implementation, the stiffening element  100  can be a polygonal or irregular shaped structure that is positioned within the barrel portion and includes at least 3 points of contact between the stiffening element  100  and the inner surface  30  of the barrel portion  18 . The stiffening element  100  is preferably formed of a lightweight, rigid material such as aluminum or polycarbonate. In other implementations, other materials can be used such as other metals, other polymeric materials, wood, ceramic, elastomers, and combinations thereof. 
     Referring to  FIGS. 10A and 10B , one example implementation of the stiffening element  100  is illustrated. The stiffening element  100  of  FIGS. 10A and 10B  is annular member having an outer surface  102  configured for engagement with the inner surface  30  of the barrel portion  18 . In one implementation, the outer surface  102  can be roughened or include serrations  104  or other structure for increasing the engagement with the barrel portion. In other implementations, the outer surface  102  of the stiffening element  100  can be generally smooth and attached to the inner surface  30  of the barrel portion  18  through a press-fit connection, an adhesive, thermal bonding, welding, other connection techniques or combinations thereof. The annular shape of the stiffening element  100  forms or defines an opening  106 . Referring to  FIG. 10B , the stiffening element  100  has a rectangular cross-sectional shape. The thickness and length of the stiffening element  100  can be varied to match a particular application or bat design. 
     Referring to  FIGS. 10C and 10D , the stiffening element  100  can be formed in annular shape with different cross-sectional shapes. The stiffening element  100  of  FIG. 10C  has a generally L-shaped cross-sectional shape and the stiffening element of  FIG. 10D  has a generally I-shaped cross-sectional shape. When the stiffening element  100  has a non-symmetrical cross-sectional shape, such as  FIG. 10C , the stiffening element  100  can be installed within the barrel portion  18  of the bat  10  with the thicker portion of the stiffening element  100  positioned closer to the handle portion  16  of the bat or closer to the end cap  38  of the bat as desired for a particular application or purpose. In other implementations, the stiffening element  100  can have an annular shape with other cross-sectional shapes such as, for example, generally U-shaped, generally T-shaped, generally V-shaped, square shaped, semi-circular, semi-ovular, other curved shapes and other polygonal shapes. 
     Referring to  FIG. 10E , the stiffening element  100  may have an outer surface  102  that defines a polygonal shape such as an octagon. In other implementations, the stiffening element  100  can have outer shapes that are triangular, square, pentagonal, hexagonal, or other polygonal shapes. The polygonal shaped stiffening element  100  engages the inner surface  30  of the barrel portion  18  at points or lines of contact  108 . For example, the stiffening element of  FIG. 10E  has eight lines of engagement or contact  108  with the inner surface  30  of the barrel portion  18 . The polygonal shaped stiffening element  100  forms a plurality of gaps  110  between the outer surface  102  of the stiffening element  100  between the lines of engagement  108  and the inner surface  30  of the barrel portion  18 . The size and number of the gaps  110  can be varied based upon a particular application. The stiffening element  100  of  FIG. 10E  also includes cross-members  112  that extend through the opening  106 . The cross-members  112  can cause the opening  106  to be a plurality of openings  106 . The cross-members  112  can intersect the center of the stiffening element  100  and the longitudinal axis  14  of the bat, and can intersect each other. The cross-members  112  of  FIG. 10E  intersect each other to form four separate openings  106  and four legs extending from the center of the stiffening element  100 . The cross-members  112  can have a thickness or width that matches the width or thickness of the outer surface  102  of the stiffening element  100 . In other implementations, the cross-members  112  can have a thickness that is less than the thickness of the outer surface  102 . In other implementations, the cross-member  112  can take other shapes, forms, numbers, and/or sizes. The cross-members  112  may form 2 or more openings  106  within the stiffening member  100 , may or may not intersect the center or longitudinal axis  14 . The cross-members  112  can be used to increase the stiffness of the stiffening element  100 . In other implementations, the cross-members can be form any shape that defines 2 or more openings within the stiffening element. 
     Referring to  FIGS. 11A through 11F , in other implementations the stiffening element  100  can have a generally disk shape. The shape and construction of the disk shape can vary. In the implementation of  FIG. 11A , the stiffening element  100  has a cup like shape or a petri-dish type shape. Referring to  FIGS. 11B and 11C , in other implementations, the stiffening element  100  can have a disk shape that resembles a puck or slug, in which the stiffening element  100  has a substantially solid circular shape. The stiffening element  100  can vary in shape, color or construction. For example, in  FIG. 11B , the stiffening element is formed of a polycarbonate material. In the implementation of  FIG. 11C , the stiffening element can be include fiber reinforcement with a polycarbonate material or other polymeric material. 
     Referring to  FIG. 11D , in one implementation, the stiffening element  100  takes the form of a honeycomb disk with a honeycomb structure  120  positioned on either side of a cross disk. Referring to  FIG. 11E , the stiffening element  100  can be a pair of circular discs  114  separated by one or more spacing elements  116 . Referring to  FIG. 11F , the stiffening element  100  can be formed of two or more separate materials such as an aluminum outer portion  122  and a polymeric inner portion  124 . The outer portion  122  can be an annular member with a cross-sectional shape similar to the above-described annular members, and the inner portion  124  can have a conical shape for facilitating some compression of the stiffening element  100 . The shape, size and material construction of the inner and outer portions  124  and  122  can be varied to match a particular application or desired stiffness value. 
       FIGS. 12 and 13A  illustrate other example implementations of the present invention in which the stiffening element  100  is shown positioned on either side of the ABI fuse region  90  within the barrel portion  18  of the bat  10  or  200 . As shown in  FIGS. 12 and 13 , the ABI fuse region  90  can be positioned on either side of the stiffening element  100  depending on a particular application or desired failure location. In  FIGS. 12 and 13A , the ABI fuse region  90  is shown longitudinally spaced apart from the stiffening element  100 . In one implementation, the ABI fuse region  90  can be longitudinally positioned with respect to the stiffening element  100  so as to within the range of 0 to 1.0 inch. In one example implementation, the ABI fuse region  90  can be longitudinally positioned so as to overlie one of the edges of the stiffening element  100 . In another example implementation, the ABI fuse region  90  can be longitudinally spaced apart from the stiffening element  100  by up to 1 inch. In another implementation, the ABI fuse region  90  can be longitudinally positioned with respect to the stiffening element  100  so as to within the range of 0.1 to 0.75 inch. 
       FIG. 13B  illustrates another example implementation of the present invention in which the ABI fuse region  90  within the barrel portion  18  of the bat  10  or  200  overlies, or is positioned at the same longitudinal location along the barrel portion  18 , as the stiffening element  100 . In  FIG. 13B , the ABI fuse region  90  is shown positioned near the center of the stiffening element  100 . However, the ABI fuse region  90  can also be positioned at any location that overlies or is in the same longitudinal location along the barrel portion as the stiffening element  100 . 
     Referring to  FIG. 14A , in another implementation, the stiffening element  100  can be formed by creating a region of increased thickness in the composite lay-up of the bat barrel portion  18 . The region of increased thickness increases the stiffness of the barrel portion  18  at that location thereby forming a stiffening element. The stiffening element  100  of  FIG. 14A  is integrally formed with the barrel portion  18  of the bat  10 . The stiffening element  100  can be formed as part of the original lay-up of the barrel portion  18  formed of fiber composite material or added during or after the lay-up of the barrel portion  18  as part of a co-molding or secondary molding process. As shown in  FIG. 14A , the ABI fuse region  90  can be positioned on either side of the stiffening element  100  depending on a particular application or desired failure location.  FIG. 14A  illustrates the ABI fuse region positioned in the bat barrel  18  to be on the end cap side of the stiffening element  100 . However, the ABI fuse region  90  can also be placed on the handle side (or opposite side) of the stiffening element  100 . 
       FIG. 14B  illustrates another example implementation of the present invention in which the ABI fuse region  90  within the barrel portion  18  of the bat  10  or  200  is positioned at the same longitudinal location along the barrel portion  18 , as the stiffening element  100 , wherein the stiffening element is formed by creating a region of increased thickness in the composite lay-up of the bat barrel portion  18 . In  FIG. 14B , the ABI fuse region  90  is shown positioned on the barrel portion  18  at a longitudinal location near the center of the stiffening element  100  (the center of the region of increased wall thickness of the barrel portion  19 ). However, the ABI fuse region  90  can also be positioned at any location that is within the region of increased wall thickness along the barrel portion  18 . 
     Referring to  FIG. 9 , in one implementation, the bat  200  may include an ABI fuse region  90   b  positioned adjacent the endcap  38  of the bat  20 . The endcap  38  can serve to increase the stiffness of the distal end of the barrel portion  18 . In such a construction, the bat  200  may be formed with or without a stiffening element  100 . The endcap  38  essentially provides a similar function as that of the stiffening element by creating a sudden change in barrel stiffness that can force a failure or catastrophic failure of the bat barrel portion  18  during the bat rolling procedure of the ABI break-in test at the ABI fuse region  90   b.    
     Referring to  FIG. 15 , in another implementation of the present invention, an ABI fuse region  190  can be formed by adding a groove  192  within the inner surface  30  of the barrel portion  18  formed of a fiber composite material. In one implementation, the groove  192  is machined into the inner surface  30  of the barrel portion  18  after the barrel portion  18  has been laid-up and fully cured. In other implementations, the groove can be formed into the other inner surface of the barrel portion through other means such as molding. The groove  192  can be a single continuous annular groove extending completely about the inner circumference of the barrel portion  18 . The groove  192  is orientated so as to be generally perpendicular to the longitudinal axis  14 . In other words, the groove  192  can extend about a groove plane  198  that is perpendicular to the longitudinal axis  14 . The groove  192  can have a depth within the range of 5 to 75 percent of the wall thickness of the barrel portion  18  at the general location of the groove  192 . In other implementations, the groove  192  can have a depth within the range of 10 to 50 percent of the wall thickness  18  of the barrel portion. 
     The groove  192  creates a fuse or a discontinuity in the barrel portion  18  that forms the ABI fuse region  190 . The groove  192  can have a semi-circular shape. In other implementations, the groove can have other shapes such as for example, semi-ovular, triangular, rectangular, other polygonal shapes and other curved shapes. When the bat  10  with the ABI fuse region  190  is subjected to an ABI break-in test including a bat rolling procedure, the discontinuity caused by the groove  192  can result in the bat barrel portion  18  failing or catastrophically failing during the bat rolling procedure of the ABI break-in test. 
     In one implementation, the ABI fuse region  190  can be spaced apart from the end cap  38  at the distal end of the barrel portion  18  by a distance within the range of 1.0 to 4.0 inches. In another implementation, the ABI fuse region  190  can be spaced apart from the end cap  38  at the distal end of the barrel portion  18  by a distance within the range of 7.0 to 12.0 inches. 
     Referring to  FIGS. 16 through 18 , the ABI fuse region  190  can take a variety of different forms. In the implementation of  FIG. 16 , the ABI fuse region  190  is formed by two longitudinally spaced apart grooves  192   a  and  192   b . The grooves  192   a  and  192   b  can be formed in different lengths and/or widths. The grooves, such as groove  192   a , include first and second side edges  193  and  195  defined by the transition of the groove to the barrel portion  18 . The grooves, such as groove  192   a  have a width, w, within the range of 0.25 to 4.0 inches, when measured from the first side edge  193  to the second side edge  195 . In one implementation, the width w of the groove, such as the groove  192   a , can be within the range of 0.025 to 0.5 inch. The grooves  192   a  and  192   b  can be longitudinally spaced apart from each other by a distance within the range of 0.25 to 10.0 inches. In another implementation, the grooves  192   a  and  192   b  can have the same width and/or depth. In other implementations, the number of grooves  192  formed in the barrel portion  18  can be 3 or more. 
     Referring to  FIG. 17 , in another implementation, the groove  192  can be angled such that the groove  192  extends about a groove plane  198  that is angled with respect to the longitudinal axis  14  within the range of 45 to 89 degrees. Referring to  FIG. 18 , in another implementation, the ABI fuse region  190  can be formed by a spiral groove  190  formed within the inner surface  30  of the barrel portion  18 . The spiral groove  190  can be angled with respect to the longitudinal axis  14  of the bat  10  such that the spiral groove  190  extends about the entire circumference of the barrel portion  18  within a longitudinal distance of 13 inches or less when measured with respect to the longitudinal axis  14 . In other implementations, the spiral groove  190  can be angled such that the longitudinal distance required for the spiral groove to extend about the circumference of the barrel portion  18  is 7 inches or less. In another implementation, the spiral groove  190  may extend about the barrel portion  18  in a manner such that the spiral groove  190  extends over less than a full circumference of the barrel portion  18 . In other implementations, other orientations, sizes, numbers and shapes of grooves can be used to form the ABI fuse region. 
     Referring to  FIG. 19 , in one implementation, the ABI fuse region  190  can be formed adjacent to the ABI fuse region  90 . The ABI fuse region  190  can be longitudinally spaced part from the ABI fuse region  90  by a distance of at least 0.25 inch. 
     Referring to  FIGS. 20A and 21B , in other implementations the ABI fuse region  190  can be positioned adjacent the stiffening element  100 . The groove  192  can be positioned on either side of the stiffening element  100  within the bat barrel  18 . In  FIG. 20A , the stiffening  100  is a disc inserted within the barrel portion  18 , and in  FIG. 21A , the stiffening element  100  is formed by a region of increased wall thickness of the barrel portion  18  of the bat  10 . 
     Referring to  FIGS. 20B and 21B , in other implementations the ABI fuse region  190  can be positioned or located to be at substantially the same longitudinal location about the barrel portion  18  as the stiffening element  100 . In  FIG. 20B , the stiffening  100  is a disc inserted within the barrel portion  18 , and in  FIG. 21B , the stiffening element  100  is formed by a region of increased wall thickness of the barrel portion  18  of the bat  10 . The ABI fuse region  190  can be formed by placing the groove  190  at any longitudinal location along the barrel portion  18  that is aligned with the stiffening element  100 . In one implementation, the ABI fuse region  190  can be positioned longitudinally along the barrel portion  18  such that it overlies the stiffening element  100 . 
     The bat  10 ,  200  of the present invention provides numerous advantages over existing ball bats. One such advantage is that the bat  10 ,  200  of the present invention is configured for competitive, organized baseball or softball. For example, embodiments of ball bats built in accordance with the present invention can fully meet the bat standards and/or requirements of one or more of the following baseball and softball organizations: ASA Bat Testing and Certification Program Requirements; United States Specialty Sports Association (“USSSA”) Bat Performance Standards for baseball and softball; International Softball Federation (“ISF”) Bat Certification Standards; National Softball Association (“NSA”) Bat Standards; Independent Softball Association (“ISA”) Bat Requirements; Ball Exit Speed Ratio (“BESR”) Certification Requirements of the National Federation of State High School Associations (“NFHS”); Little League Baseball Bat Equipment Evaluation Requirements; PONY Baseball/Softball Bat Requirements; Babe Ruth League Baseball Bat Requirements; American Amateur Baseball Congress (“AABC”) Baseball Bat Requirements; and, especially, the NCAA BBCOR Standard or Protocol. 
     Accordingly, the term “bat configured for organized, competitive play” refers to a bat that fully meets the ball bat standards and/or requirements of, and is fully functional for play in, one or more of the above listed organizations. 
     The present invention provides a method and system for forming barrel portions of a ball bat or other cylindrical portions of a ball bat using fiber composite material that can satisfy ball bat equipment standards and/or requirements in a cost effective, reliable and high quality manner. The present invention provides a method and system for forming barrel portions of a ball bat or other cylindrical portions of a ball bat using fiber composite material that provides a high quality cosmetic appearance, is highly durable, and provides the desired operational characteristics. The present invention provides a method and system for forming barrel portions of a ball bat or other cylindrical portions of a ball bat using fiber composite material that can satisfy performance requirements, such as BBCOR certification or the USABat standard, without adding too much weight or wall thickness to the barrel portion. The present invention also provides a ball bat with a desirable level of barrel stiffness, exceptional feel and performance. 
     While the preferred embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. One of skill in the art will understand that the invention may also be practiced without many of the details described above. Accordingly, it will be intended to include all such alternatives, modifications and variations set forth within the spirit and scope of the appended claims. Further, some well-known structures or functions may not be shown or described in detail because such structures or functions would be known to one skilled in the art. Unless a term is specifically defined in this specification, the terminology used in the present specification is intended to be interpreted in its broadest reasonable manner, even though may be used conjunction with the description of certain specific embodiments of the present invention.