Abstract Global buckling failure should be avoided when designing a structure with the requirement of crashworthiness performance. This study characterises the quasi-static in-plane crushing of CF/EP composite sandwich panels by tailoring their bevel angles. A finite element model was developed describing the interlaminar and intralaminar damage of a composite sandwich panel; this model was validated by in-plane compression experiments. A numerical analysis and compression experiments were then performed to determine the responses and failure modes in the CF/EP composite sandwich panels with various bevel angles. The results showed that the global buckling-to-progressive failure transition under compression occurred in the composite sandwich panels when the bevel angle reached a critical value. A microscopic analysis showed that the composite sandwich panels with buckling failure behaviours exhibited an apparently classical post-buckling transverse shearing mode, while those with progressive failure presented individual lamina bending with inward and outward fronds. This study provides some useful data for the design of the crashworthiness of a sandwich composite panel by introducing a progressive failure mode.

中文翻译：

---

CF/EP复合夹芯板准静态面内挤压过程中从屈曲到渐进破坏的转变

摘要 在设计具有耐撞性能要求的结构时，应避免整体屈曲失效。本研究通过调整斜角来表征 CF/EP 复合夹心板的准静态平面内破碎。建立了描述复合夹芯板层间和层内损伤的有限元模型；该模型通过面内压缩实验进行了验证。然后进行数值分析和压缩实验，以确定具有各种斜角的 CF/EP 复合夹心板的响应和失效模式。结果表明，当斜角达到临界值时，复合夹芯板在压缩下发生整体屈曲-渐进破坏转变。微观分析表明，具有屈曲破坏行为的复合夹芯板表现出明显经典的屈曲后横向剪切模式，而那些渐进破坏的复合夹芯板则呈现出单个叶片向内和向外弯曲。本研究通过引入渐进式失效模式，为夹层复合板的耐撞性设计提供了一些有用的数据。