面内损伤对埋藏分层影响的三维有限元分析

3D FEM analysis of the effects of in-plane damages on embedded delamination

运用大型有限元软件ANSYS,基于复合材料层合板损伤理论,建立了含面内损伤和埋藏分层的复合材料层板三维有限元模型.分析了面内损伤对复合材料层板分层的影响.采用三维Hashin准则预测复合材料损伤,分层区损伤采用多种损伤模型,损伤发生后,认为材料仍连续,并修改损伤单元对应的材料参数.通过虚拟裂纹闭合技术(VCCT)计算分层尖端能量释放率,采用GAP元处理分层区的接触非线性问题.分析了单向轴压作用下分层区面内损伤的形式和演化过程,以及面内损伤对层间应力场、位移场以及分层能量释放率的影响.数值计算结果表明:面内损伤在降低分层区应力峰值的同时也使层间应力得到了均化,对分层扩展有屏蔽作用.

Based on the damage theory of composite laminates,a 3-D FEM model of composite laminates containing embedded delaminations and in-plane damages was developed.The effects of in-plane damages on delamination of composite laminates were investigated by ANSYS.The damage was predicted by 3-D Hashin-type criteria.The multi-kind damage model was adopted in the damage region at delamination front.The composite was still considered to be continuous after damage occurred,and the corresponding material constants of damage elements were modified.The FEM was improved with the virtual crack closure technique（VCCT）to calculate the energy release rate,and the GAP element method was used to deal with contact problems.The damage type and its evolution under uni-directional compressive load were studied,and effects of in-plane damages on interlaminar stress field,displacement field and energy release rate in the delamination region were also analyzed.The numerical results indicated that the maximum stress in the delamination region reduced,and the inter-laminar stress was homogenized caused by in-plane damages at the same time.Delamination growth was shielded.