中文摘要：

采用数值分析方法研究了冲击后含损伤的复合材料格栅加筋板的后屈曲特性。基于Mindlin一阶剪切理论和Von Karman大挠度理论，建立了冲击后蒙皮内含分层损伤复合材料格栅加筋板后屈曲分析的有限元方法；分析中同时考虑了蒙皮和肋骨中纤维断裂、基体开裂等损伤累积造成的刚度的退化和蒙皮分层子板间的闭合接触效应，为含损伤复合材料格栅加筋板的后屈曲特性研究提供了一种有效的数值分析方法。分析结果表明，蒙皮分层面积较大时，格栅加筋板出现蒙皮分层上子板的局部屈曲后仍然具有较强的继续承载能力，而在后屈曲分析中，应考虑损伤累积对格栅加筋结构承载能力的影响；采用非线性虚拟界面元可成功处理分层子板间的闭合接触效应。

英文摘要：

The buckling and postbuckling behavior of advanced grid stiffened structures with damage after impact was investigated by numerical analysis. Based on the Mindlin first order shear effect theory and the Von Karman non-linearity assumption, a finite element method was developed for the postbuckling behavior of the advanced grid stiffened structure （AGS）, considering the stiffness degradation induced by the progressive failure including fibre fracture and matrix crack. The overlap of the upper and the lower sub-laminates is overcome by a nonlinear contact element. An effective numerical method for the postbuckling behavior of the damaged advanced grid stiffened structure is provided, and the conclusions obtained in this paper can be useful for the load capacity prediction of such structures. The numerical results show that the AGS structure still has a large load capacity after the local buckling of the delaminated skin. The progressive failure analysis must be considered during the course of postbuckling analysis. Using the nonlinear contact element can avoid the overlap and penetration phenomenon between the upper and lower sub-laminates at the delaminated region.