湿热环境下考虑累积失效和分层损伤AGS结构的稳定性

Stability of advanced composite grid stiffened structures with delamination considering progressive failure and hygrothermal effects

对湿热环境下考虑累积失效和分层损伤的先进复合材料格栅加筋结构(AGS)的稳定性进行了数值分析。基于一阶剪切理论和Von Karman非线性变形假设建立了含分层损伤复合材料AGS结构的有限元模型,并推导了考虑温度和湿度效应的AGS结构有限元列式,同时给出了材料破坏准则。通过典型算例讨论了湿热环境、累积失效及分层损伤等因素对复合材料AGS结构稳定性的影响,数值结果表明当上述因素导致结构的屈曲模式发生突变时,其对AGS结构稳定性能的影响是不容忽视的。

The stability behavior of advanced grid stiffened structures （AGS） with delamination considering progressive failure and hygrothermal effects was investigated by numerical method. Based on the first order shear theory and the Von Karman non-linear assumption, the corresponding finite element formula was developed, and an appropriate progressive failure criterion was adopted. By some typical numerical examples, the effects of delamination, hygrotherrnal and the progressive failure on the stability behaviors of the AGS plate and shell are discussed. The numerical results indicate that the effects of delamination, hygrothermal and progressive failure on the stability of composite AGS structures can not be neglected when the above factors result in a jump of the buckling mode.