基于结构粘结单元的富树脂层相关罚刚度的分层精确模拟
Accurate simulation of delamination with a resin-rich layer-dependent penalty stiffness based on structural cohesive elements
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中文总结 AI 辅助
本研究通过引入富树脂层相关罚刚度增强高阶结构粘结单元，改进了分层模拟的精度与计算效率，经多种基准问题验证可提升网格收敛性与预测准确性。
中文摘要 AI 辅助
基于壳的粘结单元因罚刚度近似，往往会高估裂纹尖端前方的压缩量。本研究对作者先前开发的高阶结构粘结单元进行了增强，引入了富树脂层相关的罚刚度，以同时提升计算效率与预测精度。所提公式区分了法向和剪切罚刚度，将基于富树脂层的罚刚度从层合框架扩展至等效单层框架，该扩展通过梁理论推导得到的面外法向应力与横向剪切应力的厚度方向分布实现。所提方法经I型、II型、混合型及增强DCB构型的基准问题验证，与传统公式相比，其网格收敛性显著提升，且能更准确地预测裂纹尖端前方的压缩分布及分层扩展情况。
英文摘要
Shell-based cohesive elements tend to overestimate the compression ahead of the crack tip because of approximations in the penalty stiffness. In this study, the higher-order structural cohesive element previously developed by the authors is enhanced with a resin-rich layer-dependent penalty stiffness to improve both computational efficiency and predictive accuracy. The proposed formulation distinguishes between the normal and shear penalty stiffnesses. It extends the resin-rich layer-based penalty stiffness from the layer-wise to the equivalent single-layer framework. This extension is achieved using the through-thickness distributions of the out-of-plane normal and transverse shear stresses derived from beam theory. The proposed method is verified and validated against benchmark problems for Mode I, Mode II, mixed-mode, and reinforced DCB configurations. Compared with the conventional formulation, it exhibits significantly improved mesh convergence and provides more accurate predictions of the compression distribution ahead of the crack tip and the delamination propagation.
