LASER SHOCK WAVES FOR ADHESIVE BOND TESTING

摘要

A method based on shock waves produced by a pulsed laser is used for evaluating the bond strength between composite laminates. The laser shock wave can cause a disbond when it propagates through the adhesive/laminate interface. A good bond is unaffected by a certain level of shock wave stress whereas a weaker is damaged. The method is made quantitative and in-situ by optically measuring the sample back surface velocity with a Doppler or velocity interferometer. The interferometer signal allows distinguishing interfaces that pass the test from the ones that fail and provide an estimate of the bond strength. Experimental results confirmed by numerical simulation show that the proposed test is able to differentiate bond quality. Laser-ultrasonic inspection made on laser shock tested samples confirms that weak bonds are revealed by the method.