多层圆柱结构接触预紧力失效分析

多层圆柱结构的接触预紧问题,涉及到几何非线性和材料非线性以及接触面上摩擦力的影响。当材料间的刚度差别较大时,刚度低的材料呈现大变形特征,加大了几何非线性的程度。结构内部的预紧力的大小和分布与结构的整体刚度、结合部位的局部刚度、过盈配合间隙、接触面积等因素有关。本文对三层壳体在集中力作用下的应力和变形状态进行了数值分析。在模型建立中,接触面采用直接约束模型,摩擦力的模拟选用库仑摩擦模型,在施加预紧力时,采用了虚拟温度方法。根据数值计算结果,得到预紧力失效载荷与外壳厚度、垫块厚度和宽度、过盈配合间隙等参数的非线性关系。

FAILURE ANALYSIS OF THE MULTI-LAYER CYLINDRICAL STRUCTURE BY PRE-STRESSED CONTACT LOAD

The contact pretension between the layers of cylindrical structure concerns the non-linearity of geometry and material, as well as the influence of interface friction. When the layers are made from different materials, the less rigid layer presents more non-linear deformation. The distribution of pre-stress in the multi-layer structure is related to the global and local rigidity, the contact area and the clearance of superimposition. This paper presents the stress and strain analysis of a three-layer structure subjected to a concentrated load. In the numerical model, the direct restraint method and the Coulomb friction method are introduced. A simulated temperature method is used to realize pre-tighten force. The numerical analysis reveals the non-linear relationship between the failure load for structure and the geometry and pre-stress level of the structure.