Study On Connection Layout Designs Of The Ceramic Matrix Composite Cabins

Since the invention of ceramic matrix composites in the 1970 s,aerospace and nuclear energy engineering has promoted the rapid development of them.In the 21 st century,hypersonic weapons have become the new focus of research and become the top priority of strategic competition among big powers.As a new material for thermal structure/function integration,ceramic matrix composites are used more and more widely in hypersonic vehicles due to their superior comprehensive performance at high temperatures.With the continuous development of the preparation process,the mechanical properties of the ceramic matrix composites are getting better and better,and the application occasions gradually develop from the non-bearing members to the main bearing members.Therefore,in areas of high stress levels,the hybrid connection of ceramic matrix composites and other super alloys needs to be designed to withstand the rigors of complex loads.In the design of joint between aircraft compartments or that connecting to other axial reinforcement members,bolts is usually be used in group,the load distribution in the group is influenced by their connection stiffness.However,it's so hard in complex joint to know the connection stiffness,because of the coupling effect among them.Limited by the shape and size of connecting parts,the excessive uneven in the load distribution of the bolt group under the harsh and complex working load happens,which appearances and impairs the entire capability.In a new material application and new configuration research of the missile,it is important to find out a way to equalize the load distribution of bolt group.In order to solve the problem of uniformity of load distribution of bolt group in mixed joint structure between ceramic-composite material segment and metal's,this paper first studies the calculation principle of two-dimensional simulation model of different bolted joints,and calculates two typical examples and contrast to the result from three-dimensional solid model,the error of the two-dimensional simulation model is verified,and the Spot-weld unit is applied to the multi-row and multi-column nail distribution problem of complex connection structures in practical engineering.The global and detail FEM model is constructed using MSC.Patran/Nastran software for the composite missile cabins.A strategy is proposed to adjust the local connection stiffness.The more reasonable layout of bolt group is obtained,and the "Equal stiffness point method" is proposed to guide the design of the bolt group configuration on the butt joint.The suggested methods are valuable for other similar joint design.