关键词: 复合材料螺接接头, 力学行为, 有限元分析, 钉孔配合间隙, 预紧力-扭矩关系

Abstract: For problem of mechanical behavior study of bolted connections of fiber reinforced resin matrix composites for aviation, a refined finite element analysis method was proposed by finite element software further-development method, which concludes the high-efficiency modelling of laminates, the relationship between torque and preload, the fit clearance and slip transition section of pin hole, progressive damage judgment and performance degradation. Based on the principle of strain equivalence, the test method of preload-torque relationship of the fastener was proposed, which reduces the influence of fastener preload-torque conversion accuracy on numerical simulation accuracy. A method based on modifying the friction coefficient of the contact plane between the bolt head and the laminate was proposed to well simulate the sliding transition section on the load-displacement response for composite bolted joint considering bolt-hole clearance. The results of the load-displacement curves from experiments and finite element prediction of the single-lap composite bolted joints subjected to single-shear loading show that the maximum prediction error is 14.5%, which validates that the proposed method can effectively predict the evolution rule of mechanical behavior of composite single-bolt &multiple-bolt joints. The proposed method improves the matching degree between the prediction results and the experimental results,and it improves the finite element analysis efficiency, which lays a technical foundation of modelling for the mechanical behavior analysis of the advanced composite connection structures for aviation.

Key words: composite bolted joint, mechanical behavior, finite element analysis, bolt-hole clearance, preload-torque relationship