This paper presents the results of experimental studies examining the effect of strain rate (in the quasi-static strain-rate range from 10–8 to 10–6 s–1) on the nonlinear elastic properties of a 3D-printed photopolymer sample. The quasi-static Thurston–Brugger method, based on measuring the dependences of the relative change in the velocity of shear and longitudinal ultrasonic waves on the uniaxial compressive pressure applied to the sample, was used to measure the third-order elastic coefficients at various strain rates. In the studied strain range, a dependence of the nonlinear elastic moduli on strain rate was revealed, which may be related to the polymer’s viscoelastic properties.
Mikhalev et al. (Mon,) studied this question.