Multi-Scale Modeling of Shear Deformed Woven Fabric Composites for Progressive Failure Analysis

Abstract

Fiber reinforced composites have been widely used as structural components in automotive, aerospace, marine, sporting and leisure sectors for their high stiffness and strength to weight ratio. Particularly, woven fabric (WF) reinforced composites have received considerable attention in the above industries because of their high out of-plane stiffness, strength, toughness, and improved damage tolerance and impact resistance. In order to develop woven fabric based composite materials with enhanced reliability, it is important to consider the forming process, which is essential process in the composite manufacturing. Basically, WF is formed into the mold of a specific shape and in this process, complex behavior combining tension and shear force acts on the WF. Therefore, research work to evaluate fabric tension and shear properties has been actively conducted along with a forming analysis that can predict such WF behavior. Additionally, WFs are subjected to in-plane shear deformation during the forming process. In-plane shear deformation of woven fabric can cause an angle change between two yarn directions and consequently influence the mechanical behavior of the shear deformed woven fabric composites. The mechanical properties generally known orthotropic in-plane stiffness of the composites vary depending on the degree of shear deformation. Therefore, it is necessary to define the orthogonal properties of the new method, and it is important to study the mechanical behavior according to the shear deformation. In this study, the mechanical properties necessary for forming simulation of WF are evaluated, and in-plane shear deformation in forming process was predicted through a commercial finite element analysis software ABAQUS. U-shape and hemispherical shape pre-forming simulation and experiment were performed to employ a wide range of shear deformed WF composites. As a result, the simulation results such as shear deformation (= shear angle), WF thickness, and fiber orientation was exported to multi-scale modeling-based structural analysis In addition, to define the mechanical behavior of shear deformed woven fabric composites, multi-scale modeling was developed. Using a representative volume element (RVE) of micro-scale and meso-scale model, mechanical properties of shear deformed woven fabric composites were predicted. Strain invariant failure theory (SIFT) was applied to the multi-scale modeling to defined micro-scale fiber/matrix failure criterion. Finally, to verify the proposed model, progressive failure analysis was performed on the macroscale WF composites shape (U-shape and hemispherical shape) having various shear deformation. In conclusion, it was found that the proposed multi-scale model can be used to predict not only mechanical behavior of shear deformed W composites, but also damage progression based on micro-scale fiber/matrix failure criterion. It is expected that the newly devised material modeling technique would be widely used to design the various woven fabric composite structures.