Modelling and Simulation of Ultrasonic Guided Waves Propagation in the Fluid-Composite Structure Interaction

Abstract

The present work proposes a concept of coupling the ultrasonic guided waves (UGWs) propagation in the fluid-composite structure interaction where the composite elastic structure consists of at least two layers. This coupled multiphysics model tracks the UGWs propagation through the fluid, multilayer structure, and their interface as a part of the structural health monitoring (SHM) system to identify the damage in the structure. The model constitutes a monolithically coupled system of acoustic and elastic wave equations. The solid part comprises the Saint-Venant Kirchhoff (STVK) and neoHookean (INH) material model. The coupling between the two solid layers, and the multilayer structure and fluid inclusion is achieved via the geometric, kinematic, dynamic, interface regularity and boundary conditions. To ensure that the multilayer structure and fluid domains are conforming, we use the arbitrary Lagrangian-Eulerian (ALE) technique. The numerical solution is based on the combination of Finite Element and Finite Difference methods. Discretization is done via a Finite Element method. For this, we follow the Rothe method, in which discretization in time is followed by space discretization, solving the resulting problem according to the monolithic approach. An application example discussed here offers computational support for the off-line/passive structural health monitoring (SHM) systems for composite material and lightweight structure.