RAILCAR REINFORCEMENT DEVICE

A railcar includes a support structure and a reinforcement device. The support structure extends across a length of the railcar. The reinforcement device is coupled to the support structure. The reinforcement device includes a first surface defining a first cavity that extends through the first surface and a second surface coupled substantially orthogonal to the first surface. The second surface has substantially the same length as the first surface.

TECHNICAL FIELD

This disclosure relates generally to configuring railroad freight cars (also referred to as a “railcars”).

BACKGROUND

Railcars are configured to store and transport freight across long distances. As more freight is placed inside a railcar, the load placed on the beams of the railcar increases.

SUMMARY

Existing railcars have beams and other support structures placed throughout the railcar that support the weight of freight that is loaded into the railcar. When the load is too great, the beams and support structures may deform (e.g., bend, twist, stretch, crack, shear, tear, break, etc.). Various modifications are typically made to the beams or support structures to increase their load-bearing capacity. To increase strength in a particular area of a structure (e.g., on a side sill), a reinforcement device may be added but this can cause a stress concentration. The stress concentration may cause the reinforcement device and/or support structure to deform (e.g., bend, twist, stretch, crack, shear, tear, break, etc.).

This disclosure contemplates a reinforcement device configured in a particular manner to withstand deformation caused by stress concentrations. For example, the reinforcement device may be shaped and sized in a particular way to reduce stress concentrations. The reinforcement device may be shaped such that the edges of the reinforcement device have substantially the same length. As another example, the reinforcement device may define various cavities that control the resulting stress concentrations. By shaping the reinforcement device, the load transfer to the support structure can be directed such that stresses are minimized while providing additional strength and rigidity to the structure. Three embodiments are summarized below. The first embodiment is a railcar that includes a reinforcement device. The second is a reinforcement device. The third is a method of assembling a railcar.

According to an embodiment, a railcar includes a support structure and a reinforcement device. The support structure extends across a length of the railcar. The reinforcement device is coupled to the support structure. The reinforcement device includes a first surface defining a first cavity that extends through the first surface and a second surface coupled substantially orthogonal to the first surface. The second surface has substantially the same length as the first surface.

According to another embodiment, a reinforcement device includes a first surface and a second surface. The first surface defines a first cavity that extends through the first surface. The second surface is coupled substantially orthogonal to the first surface. The second surface has substantially the same length as the first surface.

According to yet another embodiment, a method includes welding a first surface of a reinforcement device to a support structure of a railcar. The first surface defines a first cavity that extends substantially through the first surface. The method also includes welding a second surface of the reinforcement device to the support structure of the railcar. The second surface is coupled substantially orthogonal to the first surface. The second surface has substantially the same length as the first surface.

Certain embodiments may provide one or more technical advantages. For example, an embodiment increases resistance to deformation caused by stress concentrations. As another example, an embodiment strengthens the support structures of a railcar so that the railcar can carry more weight. Certain embodiments may include none, some, or all of the above technical advantages. One or more other technical advantages may be readily apparent to one skilled in the art from the figures, descriptions, and claims included herein.

DETAILED DESCRIPTION

Railcars are configured to store and transport freight across long distances. For example, railcars may store automobiles, military equipment, livestock, construction equipment, etc. This disclosure contemplates a railcar that is configured to store any type of freight.FIG. 1Aillustrates an example railcar100.

Existing railcars have beams and other support structures placed throughout the railcar that support the weight of freight that is loaded into the railcar. These beams and support structures help prevent the sides, ends, and roof of the railcar from collapsing due to the weight of the freight inside the railcar.FIG. 1Billustrates an example railcar100and its beams and support structures. As shown inFIG. 1B, railcar100includes a support structure110(e.g., a side sill) that runs across the top of railcar100. Support structure110may be a closed section (e.g., a circular, square, or rectangular tube-like structure). Although railcars should be built to support the weight of the freight and to withstand the forces imposed on the railcar during operation of a railroad train, it is desirable to minimize the weight of each railcar so that it can carry a greater weight and/or amount of freight without exceeding the maximum weight permitted on a railroad track.

As more freight is placed inside a railcar, the load placed on the beams and other support structures, like support structure110, increases. When the load is too great, the beams and support structures may deform (e.g., bend, twist, stretch, crack, shear, tear, break, etc.). These deformations may cause the railcar's walls, ends, or roof to collapse. For example, support structure110may be a side sill that runs across the top of railcar100. As more freight is loaded into railcar100, the side sill may begin to deform, primarily near the midpoint (mid-length) of the side sill. As the area around the midpoint deforms, the roof and side walls of railcar100near the midpoint of the side sill may begin to lose support. Over time, the deformations may grow more severe and result in the side walls and/or roof of railcar100to collapse.

Due to weight and height restrictions for the railcar, it sometimes may not be possible to add more beams or support structures to handle an increased load. Instead, various modifications are typically made to the beams or support structures to increase their load-bearing capacity. For example, to minimize weight, closed section structural members such as tubes should have minimized wall thicknesses. For specific design circumstances, closed sections of square or rectangular cross-sections are fabricated to unique dimensions to minimize weight but yet retain enough strength and rigidity for the design requirements. Weight can be further reduced by adding internal stiffeners within the cross-section in specific areas, but these can cause stress concentrations that reduce fatigue life. For example, a reinforcement plate may be coupled near the midpoint of a side sill to support the side sill and to protect it against deformation. However, the reinforcement plate causes a change in thickness near the midpoint and therefore may cause stress concentrations to occur near the midpoint.

Stress concentrations can occur wherever there is a change in material thicknesses, such as when one member is attached to another member. To increase strength in a particular area of a structure (e.g., on a side sill), a reinforcement device may be added but this can cause a stress concentration. The stress concentration may cause the reinforcement device and/or support structure to deform (e.g., bend, twist, stretch, crack, shear, tear, break, etc.). One method to reduce this stress concentration and minimize weight is to modify the shape of the internal stiffener's ends such that the edges have different lengths. However, additional manufacturing steps or additional machining may need to be performed to produce a stiffener with edges that are different lengths, thereby increasing cost and manufacturing time.

This disclosure contemplates a reinforcement device configured in a particular manner to withstand deformation caused by stress concentrations. For example, the reinforcement device may be shaped and sized in a particular way to reduce stress concentrations. The reinforcement device may be shaped such that the edges of the reinforcement device have substantially the same length. As another example, the reinforcement device may define various cavities that control the resulting stress concentrations. By shaping the reinforcement device, the load transfer to the main support structure110can be directed such that stresses are minimized while providing additional strength and rigidity to the structure110.

FIG. 2Aillustrates an example reinforcement device200. As shown inFIG. 2A, reinforcement device200is coupled to a support structure110of a railcar. Reinforcement device200has a first surface205and a second surface210that is substantially orthogonal to first surface205. An edge of first surface205is coupled (e.g., welded, glued, bolted, etc.) to an edge of second surface210such that first surface205and second surface210are substantially orthogonal to each other (and e.g., conform to the internal shape of support structure110). In some embodiments, a plate is bent to form reinforcement device200so that reinforcement device200conforms to the internal shape of the support structure110prior to being attached. As shown inFIG. 2A, because first surface205and second surface210are orthogonal to each other, it becomes possible to couple reinforcement device200to orthogonal surfaces of support structure110. In this manner, two different surfaces of support structure110are strengthened simultaneously, which further increases the strength and rigidity of support structure110. As a result, railcar100is able to carry a heavier load.

Reinforcement device200has a length ‘X’ that may be any appropriate length. First surface205and second surface210has substantially the same length (e.g., ‘X’). In this manner, stress concentrations in reinforcement device210are reduced because stresses and forces are more evenly distributed across the length of reinforcement device210. The length of first surface205and second surface210is measured along the length of support structure110. If first surface205is too much longer or shorter than second surface210, undesired stress concentrations may form and result in the deformation of reinforcement device210and/or support structure110. Reinforcement device200may have a width, height, and thickness that are substantially consistent across length ‘X.’ In this manner, stress concentrations are further reduced because stress and force are more evenly distributed across the width, height, and thickness of reinforcement device200.

Reinforcement device200may be attached to support structure110by welding (e.g., skip welding) (welds215are shown). Reinforcement device200is attached to an interior surface of support structure110. As discussed above, support structure110may be a hollow structure. In these instances, reinforcement device200may be coupled (e.g., welded, glued, bolted, bonded, etc.) to an interior surface (e.g., within the hollow cavity) of support structure110. In this manner, reinforcement device200

For example, the reinforcement device200may be skip-welded inside the support structure110along its longitudinal edges. If the longitudinal edges of the reinforcement device200are of the same length, a stress concentration may be created along the transverse edge between the reinforcement device200and the support structure110. In order to reduce this stress concentration, the reinforcement device200can be shaped and its stiffness controlled to permit gradual transfer of forces from the reinforcement device200to the support structure110, thus reducing the stresses. The shape and size of the reinforcement device200modifications will depend upon the forces, moments, and their direction of application to the area.

For example, reinforcement device200may be configured to define cavities (e.g., cavities220and225) in first surface205or second surface210. Cavities220and225may be any shape and in any location of reinforcement device200. In the illustrated example ofFIG. 2A, cavity220is triangular in shape and is placed proximate a first corner of second surface210. Cavity225is circular in shape and is placed proximate a second corner of second surface210. Both cavities220and225are closed in shape (e.g., cavity220is a closed triangle and cavity225is a closed circle). The first corner and second corner share an edge that runs along the length of second surface210. That edge is opposite the edge that is coupled to first surface205. Cavities220and225may be the same shape or different shapes. The distance from cavities220and225to their respective edges and/or corners can be adjusted to reduce stress concentrations in various materials of various shapes. Cavities220and225may extend through the thickness of the surface (e.g., first surface205or second surface210) in which they are formed. Cavities220and225may control the rigidity of the reinforcement device200, and hence control the transfer of forces to the support structure110. This reduces the stress concentrations and improves the strength of the entire section. It can be appreciated that there are a variety of edge shapes or openings in the reinforcement device200near the edge that can be used to control the resulting stress concentration to desired levels.

For example,FIG. 2Billustrates a different configuration of reinforcement device200. As shown inFIG. 2B, reinforcement device200defines a triangular cavity220proximate a right edge of first surface205. Cavity220extends through the thickness of first surface205. Reinforcement device200also defines a triangular cavity230at the left edge of first surface205. Although it may be more appropriately said that cavity230defines the left edge of first surface205because it is formed from the left side of first surface205such that cavity230is open towards the left of first surface205. In contrast, cavity220is a closed triangle and not open. Although two embodiments are shown inFIGS. 2A and 2B, this disclosure contemplates reinforcement device200defining any number of cavities of any shape or size on any surface of reinforcement device200.

FIG. 2Cillustrates an example reinforcement device200attached to support structure110. As shown inFIG. 2C, a closed section support structure110is constructed by attaching reinforcement device200inside a channel section of support structure110and then adding another member235over the assembly. Member235may be a metal plate that is welded onto support structure110to close support structure110. As seen inFIG. 2C, after member235is coupled to support structure110, support structure110is a rectangular tube with reinforcement device200coupled to an interior surface of support structure110. Depending upon the loads that the area is subjected to, the reinforcement device200can be modified to control how the forces are transferred through the section.

FIG. 3is a flowchart illustrating a method300of reinforcing a railcar100. An operator or constructor of railcar100can perform method300. In step305, the operator attaches (e.g., by skip welding) a first surface of a reinforcement device to a support structure of the railcar100. The first surface may define one or more cavities that reduce stress concentrations. In step310, the operator attaches (e.g., by skip welding) a second surface of the reinforcement device to the support structure of the railcar100. The second surface may be coupled to the first surface such that the second surface is substantially orthogonal to the first surface. Additionally, the second surface may define one or more cavities that help reduce stress concentrations. In some embodiments, method300includes an additional step of attaching a metal plate to the support structure after the second surface is attached to the support structure. The metal plate may close the support structure so that it resembles a hollow tube and the first and second surfaces are attached to an interior surface of the hollow tube.