Microstructural Modeling of Three-Dimensional Woven Fiber Composites.
Nicosia, M., F. Vineis, Jeffrey M. Lawrence, and Scott T. Holmes. “Microstructural Modeling of Three-Dimensional Woven Fiber Composites.” In TEXCOMP 9 Recent Advances in Textile Composites: October 13-15, 2008, University of Delaware, John M. Clayton Hall, Newark, Delaware, USA. edited by Suresh G. Advani and John W. Gillespie. Lancaster, PA: DEStech Publications, 2008.
Composite materials are very attractive relative to metals for aerospace applications for various reasons, including weight savings, favorable thermal and acoustic properties, and corrosion resistance, among others. Three-dimensional woven fiber composite materials have the potential to be superior to the traditional unidirectional and laminate composites in terms both mechanical properties and cost-effectiveness in manufacturing. However, the use of these three-dimensional woven composite materials has been hampered by the absence of appropriate tools to predict stress and failure responses of composite components. The largest challenge in this type of modeling is the disparity in relevant length scales between the unit cell dimension and size of a typical part. To address this issue, microstructural models are used, in which the unit cell geometry is used to predict average macroscopic material properties, which can then be used to perform a stress analysis on the part of interest. Prediction of mechanical failure, however, requires knowledge of the local stress-information generally not available using averaged properties. The goal the current work is to develop a computationally feasible microstructural model for three-dimensional woven composite materials that is capable of resolving local stresses at the level of the unit cell. In general, the multi-scale model consists of two steps: (1) Pre-processing, in which finite element modeling of unit cells is used to estimate the effective material coefficients; and (2) Simulation, in which these effective material properties are used in standard finite element modeling of the component. As the simulation progresses, regions with high stresses are identified, and the unit-cell finite element model is utilized to predict the local stress within the fiber and matrix. This step is accomplished by projecting the macroscopic strain field onto the level of the unit cell to be used as boundary conditions. Preliminary simulations and future directions will be discussed.