Abstract: The invention provides an acoustic diagnosis/measurement apparatus/method using a pulse of electromagnetic force, capable of non-destructively and precisely diagnosing or measuring corrosion, adhesion, the. cover depth, and/or the diameter of a reinforcing iron rod in a structure made of reinforced concrete. A coil 12 is attached to a surface of a structure 11 including a conductor 11a and a non-conductive material 11b covering the conductor 11a. A current pulse is applied to the coil 12 thereby generating a magnetic field pulse. The magnetic field pulse causes an eddy current to be induced in the conductor 11a. The conductor 11a is oscillated by interaction between the eddy current and the magnetic field pulse. As a result, an acoustic signal is generated by the conductor 11a and the acoustic signal is converted into an eclectic signal by an acoustic transducer 14 disposed to the surface of the structure 11.

Abstract: A sensor is disclosed specifically for detecting stress waves for use in a stress wave analysis system. The stress waves-are preferably detected in a narrow frequency range of 35-40KHz. At this range, stress waves from friction and impact sources typically propagate through machine structures at detectable amplitudes. In order to maximize the signal to noise ratio of stress waves, relative to background noise and vibration, the sensor of the present invention is designed and calibrated with a frequency response and damping features that are specifically tailored for stress wave analysis.

Abstract: Method of producing a bonded wire connection between an electronic component or subassembly and a carrier by introducing energy from an ultrasound transducer into a wire that is to be bonded, wherein during the introduction of energy the impedance of the ultrasound transducer is measured as a function of time, the shape of the curve representing this time dependence is evaluated on the basis of prespecified comparison criteria, and the power input to the ultrasound transducer and/or a bond weight exerted on the wire is/are controlled in dependence on the result of this evaluation.

Abstract: Thermoplastic welding is an emerging technology targeted at significantly reducing the manufacturing cost of aerospace structure by eliminating fasteners and the touch labor associated with fasteners to prepare, install, and inspect the assemblies. Quality welds are highly dependent upon achieving appropriate temperatures everywhere along the bond line. The present invention is a system that evaluates the quality of the welds involving inputting an EM pulse to the embedded susceptor and listening to the acoustic response that the pulse generates to determine weld quality from the sound.

Abstract: When electrodes on an electronic component and electrode portions on a circuit board are joined via bumps with the electronic component and the circuit board vibrated respectively, a vibration damping detect device and a deciding device detect damping of the vibration caused by a progress of joining between the bumps and the electrode portions, and then determine a good or defective of the joining on a basis of the damping of the vibration. Further, regarding an impedance of an ultrasonic oscillator, a movement amount of a nozzle, or a current supplying to a VCM, these waveforms during the joining are compared with waveforms of good joining thereof and then the good or defective is determined. According to the above constructions, the good or defective of the joining between the electronic component and the circuit board can be determined during the joining. Further, when a joining state becomes wrong during the joining, the joining state can be changed.

Abstract: A welding electrode with a configuration (2) for the ultrasound introduction for the testing of weld joints, in particular resistance welded joints, comprises an ultrasound transmitter for the impingement of the welding region with ultrasonic waves and an ultrasound receiver disposed at a spacing from the welding region, for the reception of the ultrasonic waves passed through the welding region. To provide a welding electrode which is simple in structure, which is suitable for an impingement of the welding region with longitudinal ultrasonic waves, the ultrasound transmitter radiates the ultrasonic waves axially into the welding electrode (4) or axially or obliquely into a channel (42) of the welding electrode which is filled with a medium transmitting sound.

Abstract: A material, such as a fiber composite material, has embedded inside at least one, preferably more, surface acoustic wave filters of piezoelectric material for receiving testing energy in a wireless manner and for retransmitting a material quality signal in a wireless manner which is evaluated in a system that has a wireless transmitter for sending testing energy into a material and a wireless receiver for receiving the material quality signal which is then processed and evaluated by a respective processor of the testing system. An output of the processor provides information regarding the nature and quality of the material tested and of the presence and location of any material faults that may be displayed on display screen.

Abstract: A device for detecting hidden delaminations in a structure subject to hidden delaminations comprising a rotary percussion tool head adapted at an end thereof to connect to an extension pole, wherein said head comprises at least one circular member, each circular member having on the periphery thereof projections extending in the radial direction and spaced apart in the circumferential direction, and a method of using same.

Abstract: A method for measuring the quantity of a polymeric or pre-polymeric composition within a given volume that includes combining the polymeric or pre-polymeric composition with a plurality of microparticles having a non-ferromagnetic or non-ferrimagnetic core provided with a coating that is ferromagnetic, ferrimagnetic, or conductive, to form an admixture in which the microparticles are substantially uniformly dispersed throughout the composition. The microparticles have a detectable electromagnetic characteristic which correlates with the amount of the composition within a given volume. The electromagnetic characteristic of the microparticles is then measured to determine the quantity of the composition within a given volume.

Abstract: An apparatus for testing and stress relieving metal components comprising a vibration means (28), attachment means (30), control means (2) and measuring means (13,31), the attachment means (28) being configured and arranged to, in use, directly vibration couple the vibration means (28) to a metal component (40), the control means (2) controlling actuation of the vibration means (28), and the measuring means (13,31), in use, measuring the amplitude of vibration in the said metal component (29).

Abstract: An objective and non-destructive test of the fused joints in an armature, that can be used on every armature being manufactured on an armature manufacturing line, as well as apparatus for performing that test, are provided. The armature is immersed in an acoustic coupling medium. Acoustic pulses, preferably ultrasonic pulses, are beamed onto the commutator tang/wire interface region of a commutator tang/bar fused joint or the fused joint itself and an acoustic signature is measured. The quality of the joint can be determined by comparing the acoustic signature to a predetermined acoustic signature of known quality. A testing station on an armature production line includes a mechanism for removing the armature from the production line, immersing it in the coupling medium, and rotating it as each joint in the commutator of that armature is checked.

Abstract: A system for non-destructively inspecting or testing for faults or damage in or beneath the surface of structures, such as debonds or delaminations in composite materials, or cracks, broken stringers, delaminations and the like in structures. High energy acoustic impulses are focused onto a sample point or local area for vibrationally exciting the surface of the structure under inspection. A laser Doppler camera system directs a laser beam onto the excited area and derives from reflected light energy information including time domain signals. A Fast Fourier Transform (FFT) is constructed for each sample point and an analysis made to set aside FFTs deviating from a preselected standard which represent damaged or other anomalous areas. The remaining FFTs represent an average or statistical FFT spectrum of the undamaged or fault-free area. The average FFTs and the deviating FFTs are then subtracted to provide a clear and unambiguous signal of the fault and other anomalous areas in the structure under test.

Abstract: The integrity of structures may be determined by either one of two methods. In a first method, an impulse of energy is introduced into the structure, such as by striking the structure, and the induced vibration is measured and the modal damping factor is calculated, the modal damping factor being directly related to the integrity of the structure. In a second method, a continuous energy input is provided to the structure for inducing a continuous vibration in the structure. This continuous vibration is measured with a transducer and a modal damping factor is calculated with a computer. The computer uses an algorithm to estimate the modal damping factor of the structure by calculating a theoretical response of an idealized system from several assumed parameters and varying those parameters until the difference between the measured response of the structure and a theoretical response of the idealized system is within an acceptable margin of error.

Abstract: A nondestructive inspection method predicts the lifetime of a measured object. A measured object is made to vibrate, and there is obtained a frequency difference .increment.f between a frequency of a nth-order spectrum and a frequency of a (n+1)th-order spectrum of any one of longitudinal waves, transverse waves and distortional waves generated in the measured object when the measured object is made to vibrate. It is possible to predict lifetime of the measured object by detecting degree of deterioration of the measured object based on a relational curve representing the frequency difference .increment.f and the circumstances of use of the measured object.

Abstract: An objective and non-destructive test of the fused tang/commutator bar joints in an armature, that can be used on every armature being manufactured on an armature manufacturing line, as well as apparatus for performing that test, are provided. The armature is immersed in an acoustic coupling medium. Acoustic pulses, preferably ultrasonic pulses, are beamed onto the joint and the reflected pulses are measured. The quality of the joint can be determined by comparing the reflected amplitude to the known reflected amplitudes for joints of known quality. A testing station on an armature production line includes a mechanism for removing the armature from the production line, immersing it in the coupling medium, and rotating it as each joint in the commutator of that armature is checked.

Abstract: The fatigue integrity of metallic materials may be determined by either one of two methods. In a first method, an impulse of energy is introduced into the metallic material, such as by striking the metallic material, and the induced vibration is sensed and analyzed in order to compute the damping factor thereof, the damping factor being directly related to the fatigue thereof. With this method, a transducer is coupled to the metallic material and its output is amplified by an amplifier before input to a computer which determines the damping factor. In a second method, a continuous energy input is provided to the metallic material, such as by utilizing a frequency generator coupled to a power amplifier whose output drives a transducer such as a speaker or the like for inducing a continuous vibration in the metallic material. This continuous vibration is measured with a transducer, an amplifier, and a damping factor calculated with a computer as in the first method.

Abstract: An ultrasonic interferometry technique for composite structures such as metal/polymer/metal structures exhibits high sensitivity to interfacial properties, even at usual ultrasonic wavelengths. A model for the ultrasonic response of multilayered media accounts for viscoelasticity. Results of numerical calculations point out scaling features for interfacial properties in terms of specific stiffness S. A method is provided for characterizing the interfacial adhesion in a multilayer composite in terms of the parameter S. The multilayer composite is ultrasonically irradiated with a pulsed signal to obtain a signal characteristic of the interfacial adhesion between the multilayers. A model is provided of the multilayer composite that includes at least two additional layers which model the behaviour of the interface between the composite layers.

Abstract: A process and an apparatus for the ultrasonic testing of welds between plastic packaging like food trays and cover foils. The welded joint between the tray and cover foil is periodically exposed to pulses of ultrasonic radiation. The pulses pass through the weld and are picked up or received by a receiver. The amplitude of the received pulses is evaluated. The cross-section of the beam of ultrasonic radiation is so small that the radiation only passes through the weld itself. The packages and the ultrasonic tester are moved relative to each other in order to examine the whole circuit of the weld. The pulse rate is such that the weld areas covered by successive pulses overlap.

Abstract: Nondestructive testing of heat exchangers (12), such as a radiator, measures the percentage of good bonds between air centers and cooling tubes based on natural or resonant frequencies of the exchanger (12). The exchanger (12) is excited by an audio speaker (38) and measured for a first natural frequency in the center thereof by an accelerometer (44). The natural frequency is indicative of the percentage of good bonds in the center portion of the exchanger (12) based on the stiffness thereof. The audio speaker (38) is moved to an antinode of a higher frequency mode to measure a second natural frequency indicating the percentage of bonds at the edges and corners thereof. The resonant frequencies are compared to standards to determine the actual percentage of good bonds.

Abstract: An ultrasonic adhesion/dehesion monitoring apparatus for monitoring the adhesion/dehesion between first and second substrates comprising: a. an ultrasonic source for transmitting ultrasonic energy to at least first and second substrates; b. means for measuring the instantaneous AC current and instantaneous AC supplied to said ultrasonic source; c. means for multiplying the instantaneous AC voltage and the instantaneous AC current to determine the instantaneous power supplied to said ultrasonic source; and d. monitor means coupled to said ultrasonic source and said power determining means for monitoring the instantaneous power supplied to said ultrasonic source. Also disclosed is a method for monitoring the quality and/or adhesion/dehesion between first and second substrates in the ultrasonic adhesion/dehesion monitoring apparatus.

Abstract: A hand-held probe assembly has two fixed probe legs and two movable probe legs disposed in a linear array. A pair of probe legs, one of which is fixed and one of which is movable, is engageable with a first plate edge portion. A second pair of fixed and movable probe legs is engageable with a second plate edge portion. Retractable alignment legs engage a joint between the plate edge portions to aid in positioning the probe assembly relative to the plate edge portions. In an alternative embodiment of the invention, an alignment leg engages opposite sides of a joint between the plate edge portions to hold the probe assembly centered relative to the joint. The probe assembly generates electrical signals corresponding to the extent of movement of the movable probe legs. Using these electrical signals, a microcomputer calculates the peak angle and the mismatch at the joint between the plate edge portions.

Abstract: Acoustical radiation is generated and applied to the bonding interface between a radiation transmission material and a radiation attenuating material to determine adhesion quality by extraction of data from a response signal produced by echoes reflected from both the interface and the radiation entry surface on the radiation transmissive material exposed to the generated acoustical radiation. Signal phase cancellation between the echoes from the entry surface and bonding interface produce a signal signature from which the quality of bonding is evaluated. By partial attenuation of the echo from the entry surface, the signature is maximized.

Abstract: An apparatus for detecting loosening of an implant imbedded in a bone of a limb of a patient, includes a vibrator is pressed into engagement with the limb to impart vibratory motion to the bone. The vibrator is controlled to cause the vibratory motion to have a predetermined recurring pattern. A pickup device is pressed into engagement with the limb spaced from the vibrator over the same bone near the implant, for detecting the vibratory motion transmitted through the bone implant composite to generate an output signal. Implant loosening is determined when the recurring pattern of the output signal transmitted through the bone implant composite demonstrates sustained superimposition on the oscilloscope and/or significant secondary harmonics on the spectrum analyzer.

Abstract: An apparatus and method for the control and prevention of bruxing (nocturnal teeth grinding) which comprises a sound generating means affixed to the jaw of the user, an electronic control means to "read" electrical impedance variations within said sound generating means caused by bruxing and to activate an alarm when bruxing occurs. Said apparatus utilizes the principle of bone conduction wherein sonic loading of said sound generating means differs between the open-jaw and the closed-jaw states. The alarm develops a conditioned reflex in the user such that after the first few alarms incident to bruxing the user does not awaken but merely reacts by relaxing the jaw when the alarm occurs.

Abstract: A method of monitoring bonding parameters during a bonding process. The method is based on the object of continuous monitoring of bonding parameters in order to provide adjustment of bonding machines and thereby increase the reliability of the bonded connections. A bonding force is measured by a wire strain gauge attached to a bonding arm and an ultrasound amplitude is measured by a piezo-electric sensor secured to the bonding arm. The method can be used with all bonding machines which work with ultrasound.

Abstract: An apparatus and method for the control and prevention of bruxing (nocturnal teeth grinding) which comprises a sound generating means affixed to one area of the face of the user, a sound receiving means affixed to another area of the face, and an electronic control means to "read" signals from said sound receiver and to activate an alarm when bruxing occurs. Said apparatus utilizes the principle of bone conduction whereby the sonic vibrations from said second generator are transmitted to said sound receiver bottom when the jaw of the user is closed than when it is open. The alarm develops a conditioned reflex in the user such that after the first few alarms incident to bruxing the user does not awaken but merely reacts by relaxing the jaw when the alarm occurs.

Abstract: In order to guarantee a constant quality of assembled modules, bonders in accordance with the object underlying the present invention must be monitored and potentially adjusted in suitable time intervals with respect to bonding force, ultrasound amplitude and bonding time. Further, it is an advantage that the present invention has a flexible format. In accordance with the invention, the registration of the measured values ensues with a mobile, piezo-electric sensor on a table of the bonder which is no higher than integrated circuits normally processed thereon. Fields of utilization cover all ultrasound bonders for integrated circuits.

Abstract: The ultrasonic energy applied to a workpiece to be welded in an ultrasonic welding operation, over a predetermined welding time, is measured by processing the output of a load cell beneath the workpiece to produce a signal voltage for comparison with a predetermined reference voltage corresponding to the accumulated ultrasonic energy that should have been applied to the workpiece during said predetermined time to satisfactorily weld the workpiece. A one-shot timer is started at the commencement of the welding operation. If the comparison reveals that signal voltage has reached the reference voltage before the timer has run out, a success signal is generated to indicate the completion of the welding operation.

Abstract: An object to be inspected which is jointed to a circuit board is vibrated in a contactless manner by applying a gas jet or a magnetic force to the object, a laser beam is irradiated on the object, and a laser beam reflected from the object is detected by a linear sensor to observe a laser speckle pattern for the object. Quality of a joint junction state of the object is judged from the laser speckle pattern.

Abstract: A method and apparatus for detecting disbond in laminar workpieces. Energy is transmitted to a workpiece (8) by repetitive impacts. A transducer (12) converts energy emitted from the workpiece (8) to an electrical signal. The energy emitted in response to each of the repetitive impacts is analyzed. After filtering out the DC component (20) and amplifying the signal (30) the maximum amplitude of the energy from each impact is selected (50) and passed to a sample and hold circuit (60). The piecewise linear output of the sample and hold circuit (60) is passed through a low pass active filter (70) prior to recording on a strip chart recorder. The strip chart record is analyzed to ascertain areas of the workpiece (8) having defective clad bonding (7).

Abstract: Apparatus and method for testing structures by impact. The structure is struck by an impactor associated with a force transducer the output of which is related to the force which the transducer experiences on impact and encompasses a frequency range including the lowest frequencies (typically approaching zero frequency, see FIG. 3) which that force contains to any substantial degree. A test spectrum of the force including that full range of frequencies is produced by a Fourier transformer in a form suitable for automatic comparison, and is then so compared with a reference spectrum typical of impact with a reference structure, and a signal is produced indicating fit or lack of fit between the test and reference spectra.

Abstract: The invention relates to a device for the automatic checking of welds between tubular parts. A carriage comprises two fixed ends with their centering wheels, a movable mechanism with two flanges and guide rails. This mechanism rotates on bearings. The carriage includes a drum moving over rails and bearing a telescopic arm orientable by rotation on its axis. The end of the arm carries an inspection head. Digital control ensures the programming of the movement and the orientation of the inspection head opposite the weld. The device and method are useful for the ultrasonic checking of the welds of the nodes of offshore platforms and for the checking of welds in nuclear power systems.

Abstract: A method and a system for testing the bonding of foam insulation (22) attached to metal. The system involves the use of an impacter (10) which has a calibrated load cell (12) mounted on a plunger (14) and a hammer head (16) mounted on the end of the plunger (14). When the impacter (10) strikes the insulation (22) at a point to be tested, the load cell (12) measures the force of the impact and the precise time interval during which the hammer head (16) is in contact with the insulation (22). This information is transmitted as an electrical signal (20) to a load cell amplifier (28) where the signal (20) is conditioned and then transmitted to a Fast Fourier Transform (FFT) analyzer (34). The FFT analyzer (34) produces energy spectral density curves (power plotted against frequency in Hertz) which are displayed on a video screen (39). An operator, by observing the frequency point at which the curve terminates, may determine the quality of the bond.

Abstract: A method of ultrasonically inspecting the internal structure of a multi-ply composite material using ultrasonic transducers includes the steps of positioning an ultrasonic transmitter in acoustical contact with one surface of the material, directing a beam of acoustic energy into the material with the angle of incidence of the beam with respect to the surface being less than the second critical angle for the material but greater than normal to the surface, and receiving the reflected energy. In one embodiment, the transmitting and receiving transducers are positioned with their axis perpendicular to the orientation of the reinforcing fibers within the ply being inspected. In another embodiment, the transmitter and receiver are aligned at equal angles on either side of a line which is perpendicular to the orientation of the fibers. The receiver may be located on the same or the opposite side of the material from the transmitter.

Abstract: A method of inspecting non-destructively a specimen for examining the presence or absence of a defect in the specimen, in which an ultrasonic wave is emitted from a probe and a reflected wave from the specimen is received by the probe whose output signal is processed to determine the presence or absence of the defect. The signal processing includes steps of extracting characteristic parameters from a frequency spectrum of the ultrasonic echo and comparing the extracted parameter with corresponding experimentally or theoretically determined values. The invention makes it possible to automatically determine discriminatively whether the reflector of the ultrasonic echo is a configured portion, a weld boundary or a defect of a specimen to be inspected.

Abstract: Welded joints of austenitic steels are tested by ultrasonic sound caused to be incident on the joint at an oblique angle thereto. Information regarding the size and nature of reflectors in the joint can be derived from the amplitude of the echoes generated at the reflectors in response to the sound beam. To ensure a definite relationship between the amplitude of the echoes and the nature and size of the reflector, the frequency of the sound use for testing is below and upper frequency limit at which the wavelength of sound in the base material equals the largest peak-to-valley distance of the base metal weld interface in any of the consecutive areas of the interface on which the sound beam is incident at any time.

Abstract: A method for detection of unacceptable solder joints, especially solder pads on printed circuit boards (PCBs), by means of the application of acoustic vibrations over a range of frequencies to the solder joint and observation of the acoustic impedance of the joint as reflected back through the driver to the acoustic generator or through an acoustic detector near the generator to electrical detecting apparatus.

Abstract: The integrity of mine roofs and rock bolts is tested by determining the natural frequencies of the roof and bolt. The roof is struck at a plurality of locations and the resulting vibrations sensed with accelerometers. The output of each accelerometer is separated into a plurality of signals of different frequencies by a comb filter having selected band passes. The amplitude of the outputs of each of the band passes of the filter are used to determine the condition of the roof and bolt adjacent each accelerometer. The high amplitude signal resulting from the initial impact of the striking implement is electrically gated from the accelerometer output.

Abstract: In detecting, characterizing or studying flaws in work whose surface is irregular by acoustic imaging in which a holographic pattern is produced the irregular surface is scanned by acoustic energy focussed on or near the irregular surface and the reception of the acoustic energy resulting from echoes from flaws is controlled for each scanned elemental area so as to reduce to a negligible magnitude the effects or variations in the acoustical path caused by the irregularties at different elemental areas in accordance with the irregularity at that area. The control may be effected by filling in the depressions in the irregular surface with an acoustic energy absorbing material such as butyl rubber or with a material, such as wax, which is not wetted by the liquid through which the acoustic energy is propagated to the surface.

Abstract: A non-destructive bond testing apparatus utilizes impedance variation represented by both the phase and amplitude of the signal vector response of a sonic energy generating and receiving probe, which is applied to a laminar, honeycomb or fiber composite structure under test. Typical bonding methods for which this bondtester and method are applicable include adhesive bonding, diffusion bonding, brazing, resistance and impact/friction bonding. A cathode ray tube displays the tip of the vector (as a bright dot) which represents the impedance characteristic affected by the structure under test.

Abstract: The integrity of attachment of bolts in a substrate such as a wall of a mine is tested by introducing vibratory energy into an exposed end portion of the bolt and ascertaining the vibratory energy absorbed by the bolt and its attachment.

Abstract: A beam lead device which has been thermocompressively bonded to a substrate is non-destructively tested to determine the strength thereof by directing a short burst of air at the device and detecting the Stress Wave Emission (SWE) signals emanating from the bond site subsequent to said burst of air. The SWE signals are then processed to determine the strength of the adhesion bond.

Abstract: The bond integrity of resin grouted rock bolts or roof bolts anchored within the ceiling in underground mines is tested by inducing broadband vibrations and measuring the resonant frequencies of the axial and transverse vibration modes. Voids in the resin grout or imperfect bonding cause shifts in the resonant frequencies. The tension in expansion nut rock bolts is determined from the resonant frequency of the transverse vibration mode.