侧边边界条件对复合材料加筋板轴压载荷下屈曲和后屈曲性能的影响

Influence of side boundary condition on buckling and post-buckling performance of composite stiffened panels under axial compression load

为研究侧边边界条件对复合材料加筋板压缩稳定性能的影响,首先采用有限元软件对压缩载荷作用下的复合材料加筋板进行建模数值计算,得到加筋板在侧边简支和自由2种边界条件下的屈曲载荷和形式,然后采用工程计算方法对加筋板轴压承载能力进行了估算,参考计算结果,分别对侧边有支持和侧边自由2组加筋板进行轴向压缩试验,分析侧边边界条件对试验件的屈曲形式、屈曲载荷以及后屈曲破坏过程的影响。试验结果表明:侧边支持条件会影响加筋板的屈曲形式和破坏形式。对于侧边有支持的试验件,屈曲后整体变形较小,筋条的压缩断裂是主要的破坏形式;而侧边自由的试验件屈曲后会逐渐出现整体弯曲变形,变形引起的筋条脱粘和弯曲断裂则是主要的破坏形式,且筋条脱粘会显著降低结构的承载能力。有限元计算结果与试验结果较吻合,验证了有限元模型的合理性。采用工程计算方法对侧边有支持的加筋板承载能力进行估算具有较好的精度。

To analyze the influence of side boundary condition on the compression stability performance of composite stiffened panel,finite element software was adopted firstly for modeling and numerically simulating of composite stiffened panel under axial compression to obtain the buckling load and buckling pattern of the panel with unloaded edges simply-supported or unsupported.Then,load carrying capacity of the panel was estimated by engineering calculation method.According to the calculation results,axial compression tests on composite stiffened panels were conducted to analyze the influence of side boundary condition on the buckling pattern,buckling load and post-buckling failure process of the specimen.Test results show that,side boundary condition affects the buckling pattern as well as failure pattern of the stiffened panel.For specimens with unloaded edges supported,the overall deformation after the buckling is slight and the main failure pattern is the compression fracture of stiffeners.For specimens with unloaded edges unsupported,debonding and bending fracture of stiffeners caused by overall deformation after buckling are the main failure patterns,and the debonding of stiffeners decreases the carrying capacity of the structure obviously.Finite element calculation results accord with the test results well,which validate the rationality of the finite element model.It is of preferable accuracy to estimate the carrying capacity of stiffened panels with unloaded edges simply-supported by engineering calculation method.