关键词: 复合材料层合板, 有限元分析, 沉头, 渐进损伤, 连接强度

Abstract: In this paper, based on the theory of three-dimensional progressive failure, Tserpes failure criterion and its further stiffness deterioration criterion are introduced to build the models of double-bolt, single-lap, countersunk composite joints. Experimental verification is carried out to prove the numerical simulation model. It is demonstrated that end distance, width and tightening torque can improve the structural strength in different extent. And, damage propagation process is simulated visually. The results indicate that the joint strength is enhanced obviously during the process of end distance-diameter from 2 to 4, width-diameter ratio from 3 to 5 and tightening torque from 0 to 5.9 N·m. It′s earlier and more serious than bolt-1 in static tension that the damage around bolt-2 will eventually lead to joint failure. The damage in the 90° layer is mainly matrix cracking which occurs the earliest. The weakest damage occurs on 0° layer. As the ±45° layer, the matrix cracking spreads along the -45° of the plate, and then a large number of fiber fracture turns up along the plate width.

Key words: composite laminate, finite element analysis, countersunk head, progressive damage, connection strength