A nonlinear viscoelastic framework for elastomers in dynamic recoil

Numerous ultrafast motion phenomena in both natural and engineering systems rely on the dynamic response of soft materials during high-strain-rate recoil processes. However, conventional testing methods are constrained by limited frequency ranges and the lack of applicable conditions for soft materials, making it difficult to characterize their nonlinear mechanical behavior at high strain rates. This study employs the high-speed three-dimensional digital image correlation (3D-DIC) technique and develops a constitutive model coupling power-law elasticity with linear/fractional-order viscoelasticity to establish a theoretical framework to study the dynamic recoil behaviors in elastomers. Experimental data demonstrate that our method accurately predicts recoil velocity and recoil wave propagation in both soft materials and porous metamaterials, revealing an elastic–viscous coupling mechanism during high-strain-rate deformation. The findings offer theoretical insights and technical strategies to understand soft materials under extreme conditions and for the design of high-performance soft robotic and metamaterial systems.