CAREER: Nested 3-D Micromechanical and Damage Models for Analysis of Pultruded and Laminated Composite Structures

提出了一种用于纤维增强复合材料结构非线性损伤分析的嵌套式三维材料和结构建模框架。不同复合材料系统的细观力学和损伤模型，如单向纤维增强聚合物(FRP)复合材料、机织和编织织物，可以直接集成在组件中：针对每个基质和纤维周期介质的弹性退化连续损伤模型，以及针对重复铺层顺序的3D子层模型。超越最初的失败。该框架是在基于位移的三维非线性有限元程序中实现的。实现了复合材料结构的渐进损伤建模。这种方法允许非线性各向异性响应，包括应变软化和损伤弹性卸载行为。纤维的破坏模式也被认识到，包括纤维微屈曲。这项研究的总体目标是加强对非均质材料的微观结构特性的理解，这些特性对复合材料结构的整体损伤响应有很大影响。

A nested three-dimensional (3D) material and structural modeling framework is proposed for nonlinear damage analysis of fiber-reinforced composite structures. Micromechancial and damage models for different composite material systems, such as unidirectional fiber reinforced polymeric (FRP) composites, woven and braided fabrics, can be directly integrated within the components: elastic-degrading continuum damage models for each of the matrix and fiber periodic medium, and a 3D sublaminate model for a repeating ply stacking sequence. The beyond initial failure. The framework is implemented within a displaced-based 3D nonlinear finite-element code. As a result, progressive damage modeling of composite structures is achieved. This approach allows nonlinear anisotropic response, including strain-softening and damaged elastic unloading behavior. Fiber modes of failure are also recognized, including fiber microbuckling. The overall objective of the proposed research is to enhance understanding of the microstructural properties of heterogeneous materials that strongly influence the global damage response of composite structures.