Implicit coupling methods for nonlinear interactions between a large-deformable hyperelastic solid and a viscous acoustic fluid of infinite extent

Abstract

This paper addresses the challenges in studying the interaction between high-intensity sound waves and large-deformable hyperelastic solids, which are characterized by nonlinearities of the hyperelastic material, the finite-amplitude acoustic wave, and the large-deformable fluid–solid interface. An implicit coupling method is proposed for predicting nonlinear structural-acoustic responses of the large-deformable hyperelastic solid submerged in a compressible viscous fluid of infinite extent. An arbitrary Lagrangian–Eulerian (ALE) formulation based on an unsplit complex-frequency-shifted perfectly matched layer method is developed for long-time simulation of the nonlinear acoustic wave propagation without exhibiting long-time instabilities. The solid and acoustic fluid domains are discretized using the finite element method, and two different options of staggered implicit coupling procedures for nonlinear structural-acoustic interactions are developed. Theoretical formulations for stability analysis of the implicit methods are provided. The accuracy, robustness, and convergence properties of the proposed methods are evaluated by a benchmark problem, that is, a hyperelastic rod interacting with finite-amplitude acoustic waves. The numerical results substantiate that the present methods are able to provide long-time steady-state solutions for a nonlinear coupled hyperelastic solid and viscous acoustic fluid system without numerical constraints of small time step sizes and long-time instabilities. The methods are applied to investigate nonlinear dynamic behaviors of coupled hyperelastic elliptical ring and acoustic fluid systems. Physical insights into 2:1 and 4:2:1 internal resonances of the hyperelastic elliptical ring and period-doubling bifurcations of the structural and acoustic responses of the system are provided.