含预制分层的帽型加筋单元在四点弯曲载荷下的损伤扩展

Damage Expansion of Cap Reinforced Element with Prefabricated Delamination under Four-point Bending Load

复合材料加筋结构在制造过程中往往会存在初始分层损伤从而降低了结构的承载能力。利用ABAQUS分析平台建立含预制分层的帽型加筋结构有限元模型,选用虚拟裂纹闭合技术中的Benzeggagh-Kenane(B-K)分层扩展判据模拟含预制分层的帽型加筋结构在四点弯载荷作用下结构裂纹的起始和扩展情况,对比试验发现结果拟合良好。详细分析分层的位置、形状及面积对加筋板损伤起始的影响,比较各型能量释放率对裂纹扩展影响。结果表明:预制分层位于界面中部时结构的承载能力最大;分层面积增大时结构的承载能力整体呈下降趋势,分层面积在一定范围变化时对结构的承载能力影响不大;但当分层面积大于一定值时,结构的承载能力急剧下降;剪切应变能释放率对裂纹扩展的贡献比较大。

During the manufacturing process,there are various forms of initial delamination,which reduces the carrying capacity of the structure in some degree. The model of cap stiffened structure was established by using ABAQUS finite element platform,and the crack initiation and propagation of cap reinforced structure under four-point bending load was simulated by using Benzeggagh-Kenane( B-K) delamination propagation criterion. The contrast between numerical simulation and experimental results shows that they fit well. The influence of energy release rate on crack growth and the effect of defect area,shape and position on damage initiation were analyzed in detail. The results indicate that the bearing capacity of the structure decrease when damage area increase,while the damage area changes in a certain range,it has little effect on the bearing capacity of the structure;when the defect is in the middle of adhesive interface,the structure has the strongest strength;shear strain energy release rate plays a leading role in damage expansion.