复合材料沉头衬套螺栓干涉连接渐进损伤数值模拟分析方法

The strength-enhancing interference-fit sleeved bolt joint has evolved into a advanced joint design for carbon fiber reinforced polymer(CFRP) structures. However, under complex axial and radial installation loads, the sleeve is prone to non-uniform plastic deformation, leading to uneven damage distribution and reduced joint quality. An experimental study is conducted to investigate the installation behavior of CFRP interference-fit joint with sleeved bolt. A progressive damage model based on the strain-based 3D-Hashin criterion and continuous stiffness degradation theory is proposed to simulate the intra-laminar damage behavior of CFRP during interference-fit installation. Additionally, a cohesive zone model is employed to reveal the initiation and propagation of delamination. The results indicated that the finite element model showed good agreement with the experimental results. During installation, the countersunk sleeve material is flowed and accumulated towards the exit, with the radial displacement of the hole wall gradually increasing along the installation direction. The damage is most severe at the hole wall exit, with the largest area of matrix compression damage, which follows a distribution trend similar to the radial displacement of the hole wall. When the interference-fit size of the sleeved bolt is designed to be 3%, it can effectively control interference installation damage while reducing the hole-making precision requirements.