A method and apparatus for the non-destructive testing of materials, particularly composite structures and other such laminated materials, which comprises repeatedly impacting the material being tested with a precisely regulated force having a pre-determined magnitude. The response generated by the material is detected by a sensor and a proportional electrical signal is generated. The electrical signal is compared with a stored electrical signal previously generated in response to impacting a defect-free reference material with the same precisely regulated pre-determined force. A difference in frequency and amplitude between the two compared electrical signals is indicative of a defect in the material being tested.

Method and apparatus for the non-destructive testing of materials

Apparatus and methods for effecting ultrasonic bonds in sequentially advancing workpiece segments, in a nip defined by a rotary ultrasonic horn and rotary anvil roll. The ultrasonic bonding apparatus comprises support structure comprising anvil support apparatus and horn support apparatus. A closed loop control apparatus is connected to one or both of the anvil support apparatus and horn support apparatus. The closed loop control apparatus comprises a programmable logic controller, a load cell, and an adjustor. Information output from the load cell triggers the closed loop control apparatus through the programmable logic computer and the adjustor to move one or both of the anvil support apparatus and horn support apparatus toward or away from the other in dynamic response to the information output from the load cell, thereby regulating pressure in the nip with ongoing real-time adjustments to distance between the anvil support apparatus and the horn support apparatus.

Load cell closed loop control for rotary ultrasonic bonding apparatus

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.

Testing of structures by impact

An improved non-destructive sonic testing apparatus is disclosed which is specially adapted for use in assessing the integrity of wooden utility poles. In one embodiment, the sonic testing apparatus of the present invention operates to perform a Fourier analysis on a signal which has been transmitted through a pole to be tested. Two or more criteria selected from the group of mode, mean, median and range are then determined for the resulting waveform and compared in order to provide a visual display representative of the condition of the pole being tested. In another embodiment of the present invention a software peak seeking algorithm is utilized to provide an envelope waveform from which successive half lives are determined. The relative time duration for successive half lives are compared to provide an indication of the amount of decay.

Sonic wood testing apparatus and method

This invention pertains to apparatus and methods for creating ultrasonic bonds in sequentially advancing absorbent article workpiece segments, in a bonding nip. The ultrasonic bonding apparatus comprises a frame, anvil support apparatus, horn support apparatus, closure apparatus, a load cell support member, and a load cell. The ultrasonic horn and the anvil roll collectively are mounted and configured such that the ultrasonic horn and the anvil roll can be brought together, via the closure apparatus, to define the nip therebetween. The load cell is mounted to the load cell support member such that force representative of force exerted on the anvil roll at the nip is detected by the load cell. In preferred embodiments, the invention includes outputting information from the load cell and adjusting force in the nip in response to the information received from the load cell.

Rotary ultrasonic bonding apparatus and methods using load cell

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. Specifically, the termination frequency of the energy spectral density curve may be compared with a predetermined empirical scale to determine whether a high quality bond, good bond, or debond is present at the point of impact. For future reference and use, data from the FFT analyzer (34) are recorded on a magnetic disk (41) and/or a hard copy is produced by a printer (43).

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Archie D. Coleman

Papers

Insulation bonding test system