The purpose of this study is to develop an approach to generate reasonably conservative estimations of the residual strength of a composite material with barely visible impact damage (BVID) without directly modeling the dynamic impact process. During an impact, a portion of the impactor kinetic energy transforms into the formation of a microcrack system in the matrix, fiber, and interface, which can be interpreted as material damage. Using the estimated value of energy transformed into damage as a constraint in the mathematical formulation, the optimization algorithm computes the damage distribution to minimize the residual stiffness of the structure as an objective function, which is closely related to the residual strength. Thus, this procedure gives “the worst” possible damage distribution within the material as a conservative estimation of the residual strength of the composite part. The proposed approach is promising for establishing the allowable BVID with fewer experiments.

这项研究的目的是开发一种方法，以生成对复合材料具有几乎看不见的冲击破坏（BVID）的残余强度的合理保守估计，而无需直接对动态冲击过程进行建模。在撞击过程中，撞击器动能的一部分转化为在基质，纤维和界面中形成的微裂纹系统，这可以解释为物质损害。优化算法使用转化为损伤的能量的估计值作为数学公式的约束条件，计算损伤分布以将结构的残余刚度最小化为目标函数，该残余刚度与残余强度密切相关。从而，这个过程给出了材料中“最坏”的可能损坏分布，这是对复合零件残余强度的保守估计。提出的方法有望通过较少的实验来建立允许的BVID。