RIA: Damage Evolution Based on Distributed and Localized Changes of Microstructure

本文的研究目标是：1)建立基于规范原理的具有场方程和边界条件的损伤连续统理论；Ii)使用符号计算和与有限元代码的直接接口全面实现理论；Iii)基于纤维微屈曲连续损伤理论的分岔分析，研究整体失稳与局部压缩破坏的相互关系；（四）对复合材料气瓶进行复合载荷下的压缩试验，以确定破坏微观机制并与理论预测相关联。本文的研究将对组合荷载下易发生压缩破坏的复合结构的优化设计产生影响。它还将通过确定失效的微观机制来改进高性能复合材料制造过程的建模。

The objectives of the proposed research are 1) to develop a continuum theory of damage with field equations and boundary conditions based on the gauge principle; ii) to fully implement the theory using symbolic computations and direct interface with a finite element code; iii) to investigate the interrelation between global instability and local compressive failure based on bifurcation analysis of the continuum damage theory with connection to fiber microbuckling; iv) conduct compression tests on composite cylinders under combined loading in order to identify the failure micromechanisms and correlate with theoretical predictions. The proposed research will have an impact on the optimum design of composite structures loading under combined loading and prone to compressive failure. It will also improve the modeling of manufacturing processes for high performance composites by identifying the micromechanisms of failure.