Debonding mechanism analysis of ice-rock interface using frequency domain generalized multi-symplectic method

The normal debonding of the ice-rock interface subjected to dynamic loads with certain frequencies threatens the safety of defense equipment deployed in the polar region. Capturing the frequency of the dynamic load that can excite the debonding behavior on the ice-rock interface cannot be achieved successfully by solving the dynamic model in time domain. The frequency domain generalized multi-symplectic method (FD-GMSM) is developed to reveal the debonding mechanism of the ice-rock interface in this paper. Based on the Hamiltonian variational principle, the ice-rock interaction dynamic model considering the viscoplasticity of the ice, the linear elasticity of the rock, as well as the spring-damping bond property of the interface is established. Then, a FD-GMSM is proposed to perform the high-fidelity simulation of the ice-rock interfacial debonding, which performs the structure-preserving iteration for the dynamic response of the interfacial debonding. Compared to the Fourier transform method (FTM) for time domain integral results, the low simulation cost and the stable multi-symplectic residual of FD-GMSM are presented in the results of the frequency domain simulation. In the simulation, the resonant frequency distribution of the ice-rock system is captured, the significance of which is that, the resonation in the system amplifies the interfacial normal stress to exceed the critical bond strength. The aforementioned results reveal the quadratic nonlinear relationship between the resonant frequency value and its order. Furthermore, the number of the interfacial debonding regions is positively correlated with the order of the resonant frequency, which implies that more interfacial normal stress peaks can be obtained when the excitation frequency equals to a higher order resonant frequency of the system. The verified results reported in this paper imply that, the proposed FD-GMSM can be used to predict the debonding behaviors of the ice-rock interface, which will further be used to guide the site selection of the important defense equipment in the polar region.