Nondestructive evaluation of crazes and microcracks on polymers by the elastic-wave transfer function method

Abstract

The precise study of the relation between microdefects such as crazes or microcracks and the elastic-wave transfer function method (ETFuM) was conducted in acrylonitrile butadiene styrene and acetal homopolymer. The ETFuM is the method of comparing the input elastic wave and the output wave from the specimens, and separating and analysing only the information on the object condition in the specimen from the transfer function in the frequency domain. In order to investigate the formation of crazes or microcracks caused by tensile deformation, transmission electron microscopy and polarization microscopy was used. The variation of transfer function before/after annealing indicated the dependence on the nucleation and growth of crazes or microcracks. The results suggested that ETFuM has potential as a useful method for the analysis of the micromechanism of the deformation process during nondestructive tensile and fatigue tests on polymers.