GENERATION AND PROPAGATION OF SHEAR WAVES IN MEDIA WITH THERMAL INHOMOGENEITY OF SHEAR MODULUS

摘要

The process of the generation and propagation of shear waves in polymers with a shear modulus inhomogeneity caused by local heating was investigated. Heating was performed by an electric current passed through a wire grid embedded into a sample and by ultrasound (due to the energy absorption in the ultrasound beam focus). When a shear wave passed through a thermal inhomogeneity, the delay in the wave arrival increased. Heating of a polymer by ultrasound led to its softening in the region of the wave generation, which resulted in an increase in the duration and peak amplitude of the shear pulse.