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

提出的研究目标是：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体理论；2)利用符号计算和直接与有限元程序的接口实现该理论；3)基于与纤维微屈曲有关的连续体损伤理论的分叉分析，研究整体失稳和局部压缩破坏之间的相互关系；四)对复合载荷下的复合材料圆筒进行压缩试验，以确定失效的微观机制，并与理论预测相关联。本文的研究将对复合材料结构在复合荷载作用下的优化设计产生一定的影响。它还将通过识别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.