Viscoelastic–plastic constitutive model with damage of frozen soil under impact loading and freeze–thaw loading

Abstract

This study aims to provide an understanding of the damage evolution and dynamic mechanical behavior of frozen soil under freezethaw (F-T) loading and impact loading.We used the split Hopkinson pressure bar (SHPB) device to evaluate the dynamic mechanical properties of frozen soil at different numbers and temperatures of F-T cycles. Our results indicate that the F-T process has a strong influence on the dynamic mechanical behavior of frozen soil. The peak stress of the frozen soil gradually weakens with an increase in the number of F-T cycles until the cycle number reaches the critical value for the steady state of the soil specimen (approximately 37 cycles). We observed a decrease in the peak stress of the frozen soil with a decrease in freezing temperature. We defined the F-T damage using wave impedance, which characterizes the microstructural properties of frozen soil, coupled it with the impact damage that satisfies the twoparameter Weibull distribution, and obtained the total damage of the frozen soil under F-T loading and impact loading. By combining the discretized ZhuWangTang (ZWT) model with the plastic theory that satisfies the DruckerPrager (D-P) yield criterion, which is based on the improved hardening criterion with strain rate terms, we constructed a viscoelasticplastic constitutive model with damage in frozen soil under F-T loading and impact loading. The results predicted by this model agree with the experimental data, validating its feasibility.