Coupled Finite Element and Cellular Automata Methods for Analysis of Composite Structures in an Acoustic Domain.

摘要

This study examines various computational techniques to analyze dynamic response and failure of sandwich composite materials subject to fluid- structure interaction characterized by an acoustic field or the propagation of velocity potential according to the wave equation. A displacement-only plate finite element is developed and implemented using Discontinuous Galerkin (DG) methodology; its accuracy compares favorably to both theory and Continuous Galerkin methods. Several approaches to analyzing debonding failure between skin and core layers of sandwich composite structures are demonstrated and evaluated; partial disconnection between neighboring elements at a debonding site shows good qualitative agreement with known physical phenomena. A hybrid Finite Element-Cellular Automata (FE+CA) approach to modeling an acoustic field with non-reflecting boundary conditions is presented, validated numerically, and favorably compared with experimental results. The FE+CA fluid model is then combined with the DG structural model to simulate fluid-structure interaction; this combined model compared favorably with experimental results for the strain field of laminated plates subject to low-velocity impact. Each technique addressed shows promise for flexible and accurate modeling of failure initiation and propagation in sandwich and laminate composites subject to fluid-structure interaction with moderate computational costs.