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复合材料层合板的干涉配合连接具有优越的性能,是飞机复合材料结构连接的发展趋势。然而,层合板在干涉连接过程中易出现分层损伤。针对以上问题,采用理论建模与有限元模拟方法研究了碳纤维增强树脂基复合材料(CFRP)层合板干涉螺接过程中的分层损伤及其临界干涉量。首先,对CFRP层合板的干涉螺接工艺过程和分层损伤进行力学行为分析;然后,基于虚功原理,建立了各层界面的分层损伤临界轴向力计算模型,结合插钉力与干涉量间的关系,建立临界干涉量的预测模型,求得分层损伤的临界干涉量;最后,采用ABAQUS有限元软件对CFRP层合板干涉螺接过程进行数值模拟,应用内聚力单元建立层合板层间界面,模拟了CFRP层合板在不同干涉量时的分层损伤机理,并通过扫描电子显微镜(SEM)实验观测了细观分层损伤。研究结果显示:干涉量是影响CFRP层合板分层损伤的主要工艺参数;层合板中越靠下边的层间界面,其不产生分层损伤的临界轴向力和临界干涉量越小,即越容易产生分层损伤。
The interference fit connection of the composite laminates has the superior performance and is the trend of the connection of the aircraft composite structures. However, laminates are prone to delaminations during the interference connection. In view of the above problems, the theoretical analysis and finite element simulation are used to study the delamination damage and critical interference of CFRP laminates during the interference screwing process. First of all, the mechanical behaviors of the CFRP laminates were analyzed through the interference screwing process and the delamination damage. Then, based on the principle of virtual work, the stratified damage critical axial force calculation model of each layer interface was established. Finally, the ABAQUS finite element software is used to simulate the interference screwing process of CFRP laminates, and the cohesion unit is used to establish the laminates between the laminates Interface, the layered damage mechanism of CFRP laminates at different interferences was simulated and the meso-delamination damage was observed by scanning electron microscope (SEM). The results show that the interference quantity is the main process parameter affecting the delamination damage of CFRP laminates. The more the lower delamination interface in laminates, the smaller the critical axial force and critical interference without delamination, the easier it is Hierarchical damage is generated.