几何偏差对多螺栓复合材料接头螺栓载荷和应力分布的影响研究

Effects of Geometrical Variation on Bolt Load and Stress Distributions in Multi-Bolt Composite Joints

本研究建立了考虑间隙的复合材料双搭接结构的半解析模型,描述了几何偏差对螺栓载荷和应力分布的影响.首先,从典型复合螺栓接头中提取螺栓/孔局部结构作为代表单元,建立考虑随机几何偏差与接触状态的螺栓/孔对的局部刚度模型.基于Reddy高阶剪切板理论,建立复合材料层合板有限元分析模型.将螺栓/孔对的局部刚度模型与层合板全局刚度模型相结合,形成了综合考虑螺栓/孔间隙和孔拉伸变形的多螺栓复合材料接头装配力学分析模型.随机螺栓/孔组合间隙分析结果表明,合理的螺栓间隙设置可以得到更均匀的钉载分布,为多螺栓接头的排孔设计提供理论指导.

In this paper,a semi-analytical model of the double-lap structure of composite laminates considering joint clearance is established to study the influence of geometric variations on the distributions of bolt load and stress field.Firstly,a representative bolt/hole unit is extracted from the typical composite joints,and a local stiffness model of the bolt/hole unit considering random geometrical variation and contact state is established.Secondly,based on Reddy's high order shear deforamtion plate theory,the finite element model of composite laminates is established to extract global structural stiffness matrix.Finally,by combining the local stiffness model of the bolt/hole unit with the global stiffness model of laminates,an assembly mechanical analysis model of multi-bolt composite joints is established that takes into account bolt/hole clearance and hole tensile deformation.The validity and accuracy of the model are verified by comparing it with 3D finite element simulation results.Numerical simulation results with random clearances show that a certain bolt clearance can lead to a more even bolt load distribution,providing theoretical guidance for the hole arrangement design of multi-bolt joints.