复合材料加筋结构后屈曲的自开发程序

Self-developed program for post-buckling of composite stiffened structures

针对复合材料层合加筋结构的后屈曲问题,开发出自编Fortran程序,并嵌入Patran进行前后处理。采用该程序计算出线性屈曲模态,将其作为后屈曲非线性计算的初始挠度;采用增量迭代技术、弧长控制及能量收敛准则求解非线性方程;最后引入复合材料Tsai-Hill失效准则,对单元的损伤进行判断及刚度折减。采用复合材料加筋板的压缩试验对该系统进行初步验证。针对不同加载方式、选材及结构型式的机翼盒段,利用该系统进行后屈曲计算和分析,数值结果与试验数据吻合较好。

Aircraft structures of advanced composites are usually designed to post-buckling stage so that the most loading capability could be yielded.For the problem of post-buckling of composite stiffened plate structures,the self-developed program was introduced,which was embedded into software Patran as processing and post processing.The static buckling mode was calculated by this self-developed program,and then the mode was assumed as the initiation deflection for calculating post-buckling.The nonlinear equations were solved by increment iterative,arclength control and energy convergence criterion.Introducing Tsai-Hill criterion of composite materials failure,the damage information of elements were judged and degraded.The self-developed program was verified by the compression test of composite stiffened plate.The post-buckling capacities of composite wing boxes were calculated and experimentally carried out in different cases such as loading and materials choosing,and the numerical results were in good agreement with the test data.