Estimation of elasticity and damping capacity of materials by resonant acoustic techniques

Abstract

For determine of possibility to use of new acoustic techniques with aim to study of characteristics of elasticity and internal friction in different classes of materials, single crystal of KBr and samples of polymethylmethacrylate (PMMA) were investigated using developed program of resonant ultrasound spectroscopy at frequency range of 20 to 100 kHz. It was found that the calculated elastic constants are consistent with literature data. It was observed that damping ratios of KBr are 0,05 to 0,33% for different modes of oscillations, and are 6,5 to 8,8% for PMMA. In contrast to Young modulus of PMMA that is independent on amplitude of strain, its damping ratio increase with amplitude, but remain stable in time.