复合材料易碎盖薄弱区结构的参数化设计

Parameterization design for weak area structure of composite fragile cover

针对复合材料易碎盖薄弱区结构进行力学性能分析,提出了薄弱区结构参数化设计方法。对发射箱盖整体进行数值模拟,确定了薄弱区局部模型分析的边界条件和载荷。计算薄弱区结构模型在11种拉弯耦合载荷作用下的承载能力,绘制强度包络线,分析了薄弱区内外侧搭接布条的长度与厚度对其性能的影响。根据最大主应力强度准则,计算得到薄弱区结构在不同拉弯比例下的强度随结构参数变化的曲线,进而对薄弱区结构进行参数化设计。根据参数化设计方法,设计了2种易碎盖进行冲破实验。结果表明,搭接长度主要影响薄弱区结构的剪切强度,而搭接厚度主要影响薄弱区结构的拉伸强度;设计结果与实验结果差距在10%左右,验证了设计方法的可行性。

Parametric design methods were proposed by the analysis of mechanical properties in the weak area of the composite fragile cover. Firstly,boundary conditions and load of the weak area were determined by numerical simulation for the whole cover.Secondly,the strength of weak area model was determined by numerical simulation under eleven different ratios of bending-stretching coupling load. The effect of thickness and length of lapped glass cloth on the strength of weak structure was discussed,and the strength envelopes were developed subsequently. Then based on the maximum principle stress rule,the curves of strength and structure parameters versus different bending-stretching coupling load were presented and parametric design method of the weak structure was proposed. According to the parametric design methods,two types of composite fragile covers were manufactured to rush experiments. The results show that shear strength is mainly affected by the length of glass cloth,while tensile strength is influenced by the thickness chiefly. The theoretical results are in close agreement with the experimental data and the mean error is about 10%,which proves the feasibility of the proposed parametric design method.