Improvement of the tensile instability in SPH scheme for the FEI (Fluid-Elastomer Interaction) problem

Tensile instability is one of the drawbacks of traditional SPH (Smoothed Particle Hydrodynamics). When SPH simulates the fluid, the pressure oscillation or non-physical phenomenon such as negative pressure and negative energy would appear. When SPH simulates the solid, the non-physical particles aggregation may even distort the results completely. Therefore, avoiding the tensile instability is one of the keys to obtain correct results for simulating the FEI (Fluid-Elastomer Interaction) problem. Therefore, this paper presents strategies for the fluid phase, elastomer phase and interaction between two phases respectively to improve the tensile instability. The feasibility and the capacity of strategies are proven by simulation of the classic FEI example and the results are compared to demonstrate the availability. Moreover, aiming at the water entry problem, several parameters influencing the response of the elastomer are discussed, which provides some regularity results to guide engineering.