Structural integrity recovery system

An apparatus and method for testing the structural joints in steel buildings is described. The invention provides electromechanical test units fixed at the joints of a building and permanently wired to a test apparatus such as an ultrasonic test monitor. Such a monitor may be one of many that are in communication with a central monitor and test management computer so as to accomplish wide spread testing of many buildings immediately after an earthquake by remote access.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to structural inspection, more particularly to the 
testing of buildings for structural integrity of joints such as welded 
joints for the anticipation of weld failure. The knowledge of such 
integrity becomes very important immediately after an earth upheaval such 
as a natural quake or other disturbances such as a terrorists event such 
as a bombing, foundation settlement or unexpected dead loads imposed above 
the engineered calculations for a building or structure. 
2. Description of Related Art 
The following art defines the present state of this field: 
Weins et al., U.S. Pat. No. 4,549,437 the present invention relates to a 
method for acoustic testing of multiple segment complex structures for 
detecting changes in the integrity of such structures to anticipate 
failure. The method of the present invention in its simplest form requires 
providing each segment of a complex multiple segment structure with at 
least one acoustic sensor, recording the intensity and frequency 
distribution of the acoustic waves sensed by such acoustic sensor, and 
finally comparing the acoustic waves that are sensed either against a 
standard, over time, and/or from one segment of the complex multiple 
segment structure to another segment of the complex multiple segment 
structure. 
Penzien, U.S. Pat. No. 4,502,041 describes an offshore drilling tower has 
at least one upright hollow member extending from below the water to 
support an above-water platform. A detector in or on the hollow member, 
usually below the water, responds to a water leak into the hollow member. 
The detector includes a signal generator responsive to pressure or 
chemical effect of the water. The detector is effective when actuated by 
water intrusion into the hollow member and into contact with the detector 
to send a signal of a unique or distinct frequency through the member 
itself to a signal receiver, preferably on the platform. The receiver is 
tuned to the distinct frequency and is effective upon receipt of such 
signal to afford an indication that the detector has been actuated by a 
water leak at a particular location. Variously tuned signal generators can 
be located within and without the tower on different ones of the hollow 
members, so that each, when energized, actuates a comparably tuned 
receiver on the platform, thus affording unique indications of various 
leak locations. 
Myers, U.S. Pat. No. 5,567,881 describes an inspection apparatus and 
associated method includes a sensor housing defining an internal cavity in 
which a sensor is at least partially disposed for inspecting the surface 
of a structural part and for detecting defects in the surface and the 
substructure of the part. The inspection apparatus; includes a plurality 
of compliant fibers extending outwardly from a first end of the sensor 
housing and circumferentially about an opening defined by the first end of 
the sensor housing. The compliant fibers support the sensor housing above 
the surface of the part and maintain the sensor in a predetermined 
position relative to the surface of the part. The plurality of compliant 
fibers are adapted to flex laterally to accommodate obstructions on the 
surface of the part, such as raised fasteners, doublers or lap joints 
while maintaining the sensor in the predetermined position relative to the 
surface of the part. Consequently, the sensor can continue to acquire 
accurate signals which indicate the presence of structural defects in the 
surface and the substructure of the part as the inspection apparatus moves 
over the obstructions which protrude upwardly from the surface of the 
part. 
Hill, U.S. Pat. No. 4,057,049 describes an apparatus and methods for the 
examination of specimens, particularly human tissue in vivo, by pulse-echo 
ultrasonic methods. To compensate for the variable and unpredictable 
attenuation of examining signals when reflected from different targets 
within the specimen, the echoes are processed--for instance by frequency 
analysis--to produce at least two sets of echo-amplitude information. 
These sets of information are in turn processed to produce a quantity 
indicative of the attenuation actually undergone by signals in examining 
each particular target. This quantity may then be applied to the "A"-scan, 
"B"-scan or other displays of the echoes of the examining signals to 
compensate them for the effects of varying attenuation, The apparatus may 
also include similar uncompensated displays and displays directly 
representing the attenuation coefficients of the regions of tissue under 
scan; comparison of these with the compensated displays may reveal further 
useful information. 
Merkl, U.S. Pat. No. 5,121,628 describes an ultrasonic detection system 
having a flat faced radiator for providing a narrow beam of ultrasonic 
energy with minimal dispersion. The system includes an ultrasonic 
transmitter and receiver unit coupled to an ultrasonic transducer for 
producing ultrasonic energy. The system also includes a planar radiator 
and a coupling device between the ultrasonic transducer and the planar 
radiator. An encapsulating member surrounds the ultrasonic transducer for 
damping ultrasonic energy transmitted by the transducer in all but one 
direction. The encapsulating member is also coupled to the planar radiator 
in areas of the planar radiator that are not coupled to the coupling 
means. The encapsulating member has an area of increased density 
immediately adjacent to the planar radiator for damping the ultrasonic 
energy in areas of the planar radiator that are not directly coupled to 
the coupling means. This results in an ultrasonic detection system that 
radiates a relatively narrow beam of ultrasonic energy and in which the 
encapsulating IS member is relatively decoupled from the ultrasonic 
energy. The flat radiating face makes the ultrasonic detection system 
ideally suited for applications such as level detection and particularly 
where the radiator must be exposed to sterilizing procedures. 
Savage, U.S. Pat. No. 4,128,011 describes a method and apparatus for the 
investigation of the soundness of structures of various kinds are 
disclosed. A method which involves the transmission of a vibration wave 
through the structure in question and the detection of the frequency 
spectrum of vibration response at selected investigations. Explanation is 
given of the adaptation of this method to the continuous monitoring of 
periodic investigation of structures, with particular reference to 
offshore oil and gas platforms, to deteriorating concrete structures and 
components, and to existing bridges, tunnels and railway track systems. A 
number of elongate gauges for extending longitudinally of selected 
critical members of an offshore structure below the waterline to monitor 
its structural integrity and performance are also describes. 
Mesina et al., U.S. Pat. No. 3,936,389 describes an apparatus for the 
ultrasonic pulse-echo inspection of moving metal strip having a defect 
signal gate and a back wall signal gate adjusted to provide a back wall 
signal gate interval of fixed width and a fixed delay between the closing 
of the defect signal gate and the opening of the back wall signal gate is 
provided with means for automatically varying the time of closing the 
defect signal gate in response to changes in the relative position in time 
of the back wall signal with respect to the back wall signal gate interval 
so as to keep that gate interval in coincidence with the back wall. 
Couture, U.S. Pat. No. 3,823,603 describes an ultrasonic nondestructive 
test system as described which includes signal attenuation means. The 
system includes a transducer, a transmitter and a receiver for displaying 
on a cathode ray tube defects or other discontinuities in the workpiece. 
An attenuator circuit is coupled before the receiver and is gated on and 
off at predetermined times and especially if a receiver has been adjusted 
to a high gain for detection of small defects beneath the surface of the 
workpiece. After the receiver receives part of its initial interface 
return signal, portions of the initial interface signal are abruptly 
attenuated by gating the attenuator. 
McEachern et al., U.S. Pat. No. 5,526,694 describes an electronic measuring 
instrument measures and records the acceleration frequency spectra of a 
multi-story building while it is excited by wind. Such frequency spectra 
are indicative, in part, of building structural stiffness. When a 
traumatic structural event occurs, such as an earthquake, an explosion, or 
a hurricane, changes in wind-excited frequency spectra are used to detect 
hidden structural damage to the building. 
Matay, U.S. Pat. No. 4,004,454 describes an automatic distance amplitude 
correction device for automatically correcting for amplitude variations 
and signals caused by the attenuation of sound propagating through a test 
specimen wherein a signal is transmitted through a test specimen and the 
reflection is detected and furthermore, a through signal is detected after 
the signal has passed through the test specimen only a single time and 
utilized to provide improved automatic distance amplitude compensation. 
Sarr, U.S. Pat. No. 4,799,167 describes nondestructive ultrasonic testing 
systems and methods include data processing capabilities which allow time 
division multiplexing of several transducer channels by a smaller number 
of gates for signal processing, and time division multiplexing the outputs 
of the gates for subsequent evaluation. 
Williams, U.S. Pat. No. 5,479,825 describes an improved ultrasonic energy 
transducers each include a material contacting member secured to a 
piezoelectric element at an interface region between oppositely operated 
first and second regions of the piezoelectric element. The material 
contacting member intensifies and amplifies movement of the interface 
region as the first and second regions of tile piezoelectric element 
operated in a push-pull mode relative to the interface region. The first 
and second regions of the piezoelectric element can be electrically driven 
to move the material contacting member for transmission of ultrasonic 
energy or mechanically driven by the material contacting member for 
receipt of ultrasonic energy. A variety of piezoelectric elements can be 
used in the improved transducers including, for example generally 
rectangular bars and discs segmented into two or more portions. A variety 
of material contacting members can also be used including, for example, a 
cylindrical stud and a more narrow dowel. 
Bathmann, U.S. Pat. No. 4,492,118 describes a plate stock of uneven and 
variable thickness is tested for defects by means of ultrasonics whereby 
the zone adjacent the front surface and up to a depth of the minimum plate 
thickness is detected conventionally, but under utilization of a novel 
method the zone of variable thickness adjacent the rear wall is tested by 
detecting any echo in a gating period that is gating period during which 
either none or the rear wall echo will occur and in the latter case the 
setting up of the supplemental gating period is interpreted as having 
resulted from the presence of a defect (for example, echo 12) so that the 
occurrence of the rear wall echo 9 within the supplemental gating period 
is registered as an indication of a defect. 
Takuro, Japan, 5.142.916 describes a method and apparatus for inspecting 
rupture initiation in an article. While a load is applied to the article 
repetitively, an elastic wave is monitored by an elastic wave sensor which 
converts it into an electric signal. The electric signal is fed to a 
signal transmission device having a capacity of transmitting low-frequency 
components of the electric signal. The transmitted electric signal is 
divided into successive signal segments. The successive signal segments 
are averaged to produce an averaged signal waveform informing the presence 
of a rupture initiation in the article. 
Tadashi, Japan, 4,180811 describes a detecting device for destructive 
vibration of structures wherein detected vibration is converted into 
electric signal and an alarm is actuated when signal amount reaches at 
least one of a predetermined counting value and integration value is 
provided. The converted vibration signals are amplified, a high level 
signal in such amplified signals is detected and amplified by a high level 
detector, a high level output of this detector is counted by a counter to 
generate a counter output when the predetermined counting value is 
reached, and the alarm is actuated whenever at least one of the counter 
output and integration output is provided. 
Moore, U.S. Pat. No. 4,014,208 describes an ultrasonic system for measuring 
dimensional change in a structural member, and particularly change in a 
fastener due to tensile stress, utilizes means for double pulsing a 
transducer to transmit an acoustic pulse into the member at one end for 
reflection from its other end with a period between paired pulses selected 
to cause the second echo received of the first pulse to coincide with the 
first echo of the second pulse. A VCO is employed with a digital counter 
to time the period between paired pulses, the interval between successive 
paired pulses, and the time of a predetermined number of pulse pairs. The 
latter timing is used to alternatively shift the frequency of the VCO high 
and low to cause the first echo of the second pulse to be offset in phase 
from the coincidence position it might have at the central frequency. 
Phase detection and integration of the echo pulse coincidence during 
alternatively high and low frequency offsets produces a phase-sensitive 
feedback signal to the VCO to drive its central frequency toward precise 
coincidence. Comparing the central frequency, f, with an initial 
frequency, f.sub.o, for the unstressed condition of the member yields a 
measurement of its stress. The change (f.sub.o .fwdarw.f) is compared with 
a predetermined value, .DELTA.f, while stressing in order to adjust stress 
to that value. Initial and final conditions may be stored for comparison 
with subsequent stress measurement data. 
Saporito, U.S. Pat. No. 4,663,727 describes an ultrasonic inspection system 
for inspecting areas of tubular members and providing a display of any 
internal flaws therein. In order to operate in a confined work space a 
probe containing ultrasonic transducers is provided together with a 
rotational and axial drive scanner which is linked to a remotely 
controlled manipulator. The scanner uses a wand supporting the probe at 
the upper and thereof. The manipulator locates the probe and scanner in 
alignment with the tube to be inspected. A stepping motor on the scanner 
drives the wand and the probe axially to a location just above the area to 
be inspected. A second stepping motor rotates the wand to enable the probe 
to perform a circumferential scan. The axial stepping motor rotates the 
wand towards the lower edge of the area and another circumferential scan 
occurs. The indexing and circumferential scanning proceeds until the 
entire area is scanned. The signals received from the ultrasonic 
transducers are digitized and processed, with the aid of programmed 
digital computer, so as to graphically display the interior interface of 
the sleeve and tube which is scanned to show any voids as may be due to 
incomplete bonding between the sleeve and the tube. 
Ross, U.S. Pat. No. 4,195,530 describes an ultrasonic flaw detector for 
detecting irregularities in an object, such as a pipe, having a segment of 
annular cross-section. The detector includes a transducer with an involute 
transmitting surface for sending ultrasonic signals into the object at 
equal non-radial angles of incidence. The detector further includes a 
transmission apparatus for maintaining a constant physical relationship 
between the transducer and the pipe and interpretive apparatus for 
correlating reflections of ultrasonic signals within the object with 
irregularities. 
Myers, U.S. Pat. No. 5,567,881 describes an inspection apparatus and 
associated method which includes a sensor housing defining an internal 
cavity in which a sensor is at least partially disposed for inspecting the 
surface of a structural part and for detecting defects in the surface and 
the substructure of the part. The inspection apparatus includes a 
plurality of complaint fibers extending outwardly from a first end of the 
sensor housing and circumferentially about an opening defined by the first 
end of the sensor housing. The complaint fibers support the sensor housing 
above the surface of the part and maintain the sensor in a predetermined 
position relative to the surface of the part. The plurality of complaint 
fibers are adapted to flex laterally to accommodate obstructions on the 
surface of the part, such as raised fasteners, doublers or lap joints 
while maintaining the sensor in the predetermined position relative to the 
surface of the part. Consequently, the sensor can continue to acquire 
accurate signals which indicate the presence of structural defects in the 
surface and the substructure of the part as the inspection apparatus moves 
over the obstructions which protrude upwardly from the surface of the 
part. 
Lynnworth, U.S. Pat. No. 5,515,733 describes transducers that are mounted 
in a housing or vessel to propagate signals along a fluid measure path, 
and a plurality of massive elements are placed between transmitting and 
receiving transducers in the acoustic propagation path through the solid 
body of the housing or vessel to remove crosstalk. In a preferred 
embodiment, the elements are rings, or sleeves which are attached to, or 
are machined from a thicker cylinder to leave a thin-walled cylinder with 
alternating masses. An isolation structure lightly sandwich flange between 
O-rings. This structure may be formed with flanged transducer casings, 
allowing the transducers to be closely spaced in solid conduits or on 
rigid frames without ringing. Alternatively, it may be formed in a 
separate framework or holder, providing precise positioning for 
interrogating gases in unconfined or loosely confined regions. Closed path 
sensor configurations measure circulation or swirl. 
Takashita, U.S. Pat. No. 5,331,885 describes in an ultrasonic inspection 
system for inspecting the surface condition of an object or the existence 
or absence of internal defects in it by ultrasonically scanning the object 
with ultrasonic beams, which have been successively produced as a result 
of successive excitation of a number of array element oscillators 
(10.sub.1 -10.sup.n) arranged in a row, and then analyzing waves reflected 
by the object, reference data for individual ultrasonic beams (individual 
channels) are collected by ultrasonically scanning a reference material of 
defect-free uniform quality before ultrasonic inspection of the object. 
Correction values are prepared based on these reference data, and signals 
received by the ultrasonic scanning of the object are corrected by these 
correction values. According channels to the reference values of the 
individual channels are determined channel by channel. Using these ratios 
as correction values, they are multiplied to signals received through the 
corresponding channels. The products are used as data to be shown on a 
display unit. By these attenuation factors, signals received through the 
corresponding channels are attenuated at a sensitivity equalizer. 
Scattering in sensitivity among the individual channels can be eliminated 
by these correction means. 
The prior art teaches the use of testing of building joints including 
ultrasonic testing of joint integrity. However, the prior art does not 
teach that a testing system may be made a part of a construction and 
function in such a manner as to provide information immediately after the 
building frame is shaken. The prior art does not teach a system that allow 
testing without a partial destruction of the building's walls or other 
parts to allow access to the structural joints. The present invention 
fulfills these needs and provides further related advantages as described 
in the following summary. 
SUMMARY OF THE INVENTION 
The present invention teaches certain benefits in construction and use 
which give rise to the objectives described below. 
The present invention provides an apparatus and method for inspecting the 
welded structural joints in steel structures for the anticipation of weld 
failure without the application of any live forces being applied. The 
invention provides electromechanical test units fixed at the welded 
structural joints of a structure and wired to a test apparatus such as an 
ultrasonic test monitor. Such a monitor may be one of many that are in 
communication with a remote signal processor and test management computer 
so as to accomplish testing. 
A primary objective of the present invention is to provide a building 
integrity testing apparatus for the anticipation of weld failure without 
the application of external loads or forces and method having advantages 
not taught by the prior art. 
Another objective is to provide such an apparatus having permanent test 
fixtures as part of the construction of a building frame. 
A further objective is to provide such an apparatus having permanent wiring 
for sending and receiving test signals from a test set. 
A still further objective is to provide such an apparatus with remote 
management control and data processing. 
Other features and advantages of the present invention will become apparent 
from the following more detailed description, taken in conjunction with 
the accompanying drawings, which illustrate, by way of example, the 
principles of the invention.

DETAILED DESCRIPTION OF THE INVENTION 
The above described drawing figure illustrates the invention, a combination 
metallic building frame structural and integrity monitoring apparatus for 
the anticipation of weld failure without the application of external loads 
or forces, the combination comprising: 
a metallic building frame 5 comprising a plurality of structural elements 
10 such as steel girders, the structural elements 10 being joined by 
structure joining means 20 such as welds as shown or rivets, or other 
common building technique; 
a plurality of electromechanical transducers 30, each of the 
electromechanical transducers 30 being joined with the metallic building 
frame 5 at one of the structure joining means 20; 
a plurality of electrical signal transmission means 40 preferably either 
electrical cables or wireless links, each of the means being in electrical 
communication with one of the electromechanical transducers 30 for 
transmitting a testing signal to the electromechanical transducer 30 and 
for transmitting a test results signal from the electromechanical 
transducer 30; 
a test results signal interpretation and display means 70 interconnected 
with the plurality of electromechanical transducers 30 by the plurality of 
electrical signal transmission means 40. 
Preferably, the electrical signal transmission means 40 are coaxial cables 
for low EMF interference and for low loss signal transmission, the cables 
40 being placed within tubular cable conduit conduction means 60 for 
gaining access to an interior operating space of the building frame 5 for 
operation of the test results signal interpretation and display means 70. 
Preferably, the invention further includes a phone line transmission means 
80, such as a modem, for two-way communication between the test results 
signal interpretation and display means 70 and a central monitoring 
station data processor 90, preferably a programmable computer. 
Preferably, the central monitoring station data processor 90 is programmed 
for automatic testing of the metallic building frame 5, the data processor 
90 being enabled for sending operational commands to the test results 
signal interpretation and display means 70, again, by the modem 80 so as 
to enable the testing signals to the electromechanical transducers 30 for 
remote testing in anticipation of weld failure without the application of 
external loads or forces of the building element joining means 20. 
Preferably, the data processor 90 is further enabled for receiving the test 
results signals from the test results signal interpretation and display 
means 70 so as to enable determination of the soundness of the metallic 
building frame 5 in anticipation of weld failure without the application 
of external loads or forces. 
Preferably, the data processor 90 includes a comparitor means 92 for 
comparing the testing results signals from the test results signal 
interpretation and display means and a quality determination criteria 
stored in a memory means 94 thereof. 
Preferably, the electromechanical transducer 30 is enabled for operating 
with ultrasonic signals, i.e., the transducer is an ultrasonic type 
transducer as is well known in the building integrity testing industry in 
anticipation of weld failure without the application of external loads or 
forces. 
The method of the present invention, for remote monitoring of structural 
integrity in a building structure, comprising the steps of: 
a) joining the plurality of electromechanical transducers 30 to a plurality 
of joints 20 in a building frame structure 5; 
b) interconnecting the plurality of electromechanical transducers 30 to a 
test results signal interpretation and display means 70 with a plurality 
of permanent electrical signal transmission means 40; 
c) initiating a test signal at the test results signal interpretation and 
display means 70; 
d) transmitting the test signal to the plurality of electromechanical 
transducers 30; 
e) testing the joints 20 with the test signal; 
f) transmitting a test result signal from the electromechanical transducers 
30 to the test results signal interpretation and display means 70; 
g) transmitting the test results signal from the test results signal 
interpretation and display means 70 to a remote data processor 90 via 
modem 80. 
Preferably, the method includes the step of initiating the testing at the 
data processor 90 in accordance with a predetermined integrity monitoring 
program schedule. 
Preferably, the method includes the step of comparing the testing results 
signals from the test results signal interpretation and display means 70 
with a quality determination criteria stored in a memory means 94 of the 
data processor 90. 
While the invention has been described with reference to at least one 
preferred embodiment, it is to be clearly understood by those skilled in 
the art that the invention is not limited thereto. Rather, the scope of 
the invention is to be interpreted only in conjunction with the appended 
claims.