Numerical simulation of elastic wave based on the staggered grid finite difference method

The numerical simulation of elastic waves by the staggered grid finite difference method is researched to improve the simulation precision and efficiency, in addition, to decrease the numerical dispersion and spurious wave. Based on the velocity-stress staggered grid technique, we designed a two dimensional finite difference program with the accuracy of 0(Δ t² + Δ x⁴). More stable condition and an artificial transmitting boundary condition are applied in the program. With the program, the modeling of wave propagation in a layered model is carried out, and reasonable results are derived. Subsequently, an ultrasonic experiment of a concrete slab is conducted, and then a comparative analysis of the first arrivals of numerical simulation by staggered grid finite difference and finite element method, measurement and ray tracing is carried on. The results indicate that the travel times of the simulation by staggered grid finite difference method are in accord with that by finite element method, and closer to the measured data than those derived from ray tracing. This verifies the reliability and the anomaly recognition ability of the wave fields by the staggered grid finite difference method.