High-strain-rate response analysis of composites under laser shock with tension-compression asymmetry model

The laser adhesion test (LASAT) technique evaluates the interfacial strength of composite materials by utilizing the mechanical effects generated by laser-induced shock waves. The applied loading is characterized by a rapid transition between tensile and compressive stresses under transient loading conditions. To address the limitations of existing models that fail to simultaneously capture strain-rate effects and tension–compression asymmetry (TCA), this study develops an innovative dynamic constitutive model integrating the TCA mechanism with strain-rate dependence. Dynamic mechanical properties of the material were systematically obtained through Split Hopkinson Bar experiments, achieving strain rates up to 5000 s⁻¹ in compression and 2800 s⁻¹ in tension. The results reveal a pronounced TCA and strong strain-rate sensitivity. Based on these findings, dynamic strengthening laws were established for different strain-rate regimes. Adjustable dynamic correction factors and damping terms were introduced into the model to effectively mitigate numerical oscillations caused by abrupt modulus transitions. Validation through laser shock experiments demonstrates that the proposed model predicts free surface velocity profiles with peak deviations within 5%, cosine similarity above 0.8, and approximately 80% reduction in damage-area prediction error. Compared with models that consider only strain-rate effects or assume quasi-static behavior, the developed model exhibits superior consistency and physical fidelity in reproducing stress-wave propagation characteristics, damage distribution, and energy dissipation behavior.