Dynamic Mechanical Characteristics and Damage Modeling of Freeze-thawed Red Sandstone

To research the damage variations and dynamic mechanical attributes of freeze-thawed rocks, freeze-thaw cycle and impact dynamic compression experiments were performed on samples of water-saturated red sandstone and built the dynamic constitutive model of the entire freeze-thawed rock process by using the theory of the combined model of elements and investigating the rule of damage evolution. According to the findings, the rock specimens’ dynamic peak stress and elastic modulus are enhanced with a rise in strain rate, while these properties are reduced with an increase in freeze-thaw cycles. The experimental and theoretical curves agree, with a goodness of fit of up to 0.9457. There are three stages in a rock’s dynamic damage evolution curve: linear, nonlinear, and damage destruction. The total damage value rises with the number of freeze-thaw cycles when the strain rate is certain and decreases with the strain rate rising in sequence when the freeze-thaw cycles are certain. The damage evolution law is consistent with the macroscopic deformation and destruction.