平纹编织面板泡沫夹芯结构修补后侧向压缩有限元渐进失效分析

Progressive Failure Analysis of Repaired Foam Sandwich Structure with Plain Weave Faceplate Under Edgewise Compression

为研究修补对平纹编织面板泡沫夹芯结构侧向压缩性能的影响,通过USDFLD材料子程序,设置Tsai-Wu准则面板材料的失效判据,将线性屈曲模态考虑为初始缺陷,建立平纹编织面板泡沫夹芯结构修补后侧向压缩渐进损伤失效分析模型。结果表明,所建立模型的有效性通过试验得到了验证;面板挖补倾角在1∶10~1∶22范围内修补质量较好,且侧向压缩强度随面板挖补倾角比例的减小而增大;附加层重叠宽度在5~15mm范围内修补质量较好,且侧向压缩强度随附加层重叠宽度的增大而减小,但变化幅度不大;对完好泡沫夹芯结构或者母板损伤小的修补件,纯屈曲分析方法对其最大侧向压缩载荷的预测更加准确;夹芯结构侧向压缩的失效机理为芯材首先发生失效,然后面板发生局部屈曲,当载荷达到试件侧向压缩强度后,面板最终失效。

In order to study the influence of the scarf repair on the edgewise compression performance of the foam sandwich structure with plain weave faceplate,by the use of USDFLD material subroutine,Tsai-Wu criterion was set up for material failure of the faceplates.The linear buckling mode is considered as the initial defect,and the progressive failure analysis model for the repaired foam sandwich structure with plain woven faceplates is established.The analysis results show that the validity of the model is verified by experiments.The repair quality of the sandwich structure is better when the slope ratio of scarf repair is 1:10 to 1:22,and the edgewise compression strength increases with the decrease of the slope ratio of scarf repair.When the overlap width of the additional layer is in the range of 5mm to 15mm,the repair quality is better.The edgewise compression strength decreases with the increase of the overlap width of the additional layer,but the change range is not great.The analytical methodology involving the pure buckling analysis is more accurate to predict the maximum edgewise compression load for the intact test pieces and the repaired test pieces with little damage.The failure mechanism of the sandwich structure under edgewise compression is that after the failure of the core material,the faceplate buckles locally,and then the faceplate fails when the test piece reaches its edgewise compression strength.