Analysis of Stress, Strain and Young's Modulus of Specimens under Propagation of the 1D Linear Elastic Stress Waves

Abstract

The meticulous design and data processing of the SHPB test necessitate an exact analysis of the elastic segment to ensure an accurate acquisition of dynamic parameters. When other conditions align with theoretical requirements, a pressing question arises: Is the Young's modulus obtained through the stress wave theory while processing SHPB test data accurate? This is an issue that must be clearly addressed. To tackle this question, analytical expressions for parameters such as stress difference and particle velocity difference were derived. This allowed for the analysis of curve characteristics, influencing factors, and their underlying mechanisms. Building on this, equations for determining Young's modulus were deduced. The research indicates that when the wave impedance ratio is relatively large, the Young's modulus provided by the "two-wave method" inherently has a significant theoretical error. However, when the incident wave is sufficiently gradual, the Young's modulus deduced by the "three-wave method" proves to be remarkably accurate.