受载复合材料曲板结构的失效特征研究

为研究飞机复合材料曲板的失效过程与失效模式,对一组复合材料弯角试验件进行了准静态拉伸试验.同时基于ABAQUS软件及其USDFLD子程序,考虑复合材料的渐进损伤特征,建立了受载曲板的有限元模型,分析弯角区的应力分布特征.研究发现：数值仿真能够较准确的模拟弯角结构的受载过程,模拟结果与试验结果吻合较好;结构受载过程中,在弯角区域发生分层破坏,随着载荷的增大,分层沿着周向和径向都有扩展;随着外加载荷的增大,弯角区域的最大法向应力的位置逐渐移向加载端.

Failure property study on bent-plate structure for loading composite materials

To study the failure modes and processes of airplane composite material bent-plates, a quasi- static tractional testing is first conducted on a group of specimens. Based on ABAQUSTM software and USD- FLD subroutine, a bent-plate finite element model is then established in consideration with the progressive damage of loading composite materials. Meanwhile, the stress distribution properties are analyzed on ben- ding-angle areas. Finally, it is found that the loading process of bending-angle structures can be relatively accurately simulated using numerical simulation, whilst the results from simulation are rather accorded with those from testing. During the structural loading process, the delamination crack of bending-angle ar- eas occurs. With increase of external loadings, the delaminations are propagated in circumferential and ra- dial directions, whereas the positions of the maximum normal stress in bending-angle areas are gradually moved to the loading end.