含初始脱粘缺陷复合材料加筋壁板渐进压溃过程的数值模拟

建立了预测含初始脱粘缺陷复合材料加筋壁板渐进压溃响应的数值分析模型。该模型综合考虑了复合材料层合板的纤维失效、基体失效和纤维-基体剪切失效三种典型的面内损伤模式,并通过编写用户自定义材料子程序VUMAT实现面内失效类型的判断和相应材料性能的折减;在壁板和筋条连接界面应用虚裂纹闭合技术(VCCT)计算层间裂纹前缘的应变能释放率,并结合B-K混合模式准则控制缺陷的起裂以模拟脱粘的扩展演化过程;采用显式动力学方法准静态分析结构在压缩载荷下的屈曲、后屈曲直至最终压溃的响应过程。数值分析结果与文献试验、数值结果吻合良好,验证了模型的合理性和有效性,并详细研究了复合材料脱粘加筋壁板的损伤演化过程和渐进压溃行为。

NUMERICAL SIMULATION ON PROGRESSIVE COLLAPSE PROCESS OF COMPOSITE STIFFENED PANEL WITH INITIAL DEBONDING DEFECT

A numerical analysis model was established to study the progressive collapse behavior of composite stiffened panel with initial debonding defect.Three typical intralaminar damage modes including fiber failure,matrix failure and fiber-matrix shear failure were considered in the model.The user-defined material subroutine VUMAT was used to distinguish the in-plane failure types and to degrade the corresponding material properties.The Virtual Crack Closure Technique was applied to calculate the strain energy release rate of the interlaminar crack front and the onset of debond propagation was determined using the B-K mixed-mode criterion.The buckling and postbuckling processes up to collapse of the panel under compressive load were quasi-static solved by the explicit dynamic method.The reasonability and validity of the model were verified by the good agreement between the numerical analysis result and the literature's experimental and numerical results,and the damage evolution processes and the progressive collapse behavior of the debonded panel were investigated in detail.