Parameterization design for weak area structure of composite fragile cover

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. ©, 2015, Journal of Solid Rocket Technology. All right reserved.