含分层损伤 AGS 起裂和扩展过程数值模拟

建立了在压缩荷载下先进复合材料格栅加筋结构(AGS)后屈曲阶段的分层起裂和扩展过程的数值模拟方法.首先,基于一阶剪切变形理论和Von Karman几何非线性关系,提出了AGS结构后屈曲有限元分析模型;其次.采用总能量释放率准则,并利用虚裂纹闭合法(VCCT)及自适应网格的生成和移动技术分析了分层损伤的扩展过程,在分析过程中考虑了分层前缘的接触效应;最后,应用OpenGL实现了分层损伤的扩展动态可视化过程.通过典型算例.讨论了肋骨与分层中心的相对位置.以及蒙皮的铺层方式对AGS结构的分层起裂和扩展过程的影响.所提方法和所得结论对AGS结构的承载能力预测将具有参考价值.

Numerical simulation of delamination onset and growth process for advanced composite grid stiffened structures

A numerical method is developed to study delamination onset and growth characteristics during post-buckling process for the advanced composite grid stiffened structures(AGS) subjected to uniform axial compressive load. First, a finite element post-buckling analysis model was established based on the first-order shear deformation theory in conjunction with Von Karman nonlinear geometry theory. Second, the total energy release rate criterion combined with the virtual crack closure technique and the self-adaptive grid moving technology were used to analyze the delamination onset and growth process, which considered the contact effect of front contours of the delamination. At last, the process of the dynamic visualization is realized using OpenGL. By some numerical examples, the effects of distance from the stiffener to the circular delamination, and stacking sequence of the skin upon the delamination growth process were also discussed. The analytical method and conclusions provided can be valuable to estimate the load capability and optimal design for composite AGS.