Ndt Instruments, Inc.

John E Todd

Robert L Jones

Ronald J Botsco

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. A null circuit deletes the response of a non-flawed (or normal) portion of the structure under test so that a flawed (or abnormal) portion of the structure produces an impedance variation from the null point, the variation being represented on a polar coordinate display by the amplitude and angular position of the vector tip, thereby providing diagnostic information regarding the location and type of the bondline condition being detected. Bondline conditions/flaws detectable include, disbonds, adhesive thickness, adhesive porosity, degree of adhesive cure, adhesive (cohesive) strength and forms of in-service adhesive or bondline degradation.

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Long Beach, CA, United States of America

John E Todd