复合材料层合板贴补修理失效模式分析与修理参数选择

在对复合材料层合板进行渐进失效分析时,Zinoviev刚度退化模型是最常用的刚度退化模型之一,但是该模型涉及的参数较多并且只能用于二维问题,对其进行简化和改进后,不仅参数减少而且可以扩展至三维,基于此改进的Zinoviev刚度退化模型,结合Shokrieh改进的三维Hashin准则,采用INTER205单元对胶层进行模拟,利用ANSYS软件建立了承受面内拉伸荷载的含圆孔缺陷的复合材料层合板双边贴补修理渐进失效三维有限元模型。此有限元模型的结果和试验结果拟合得比较好,验证了改进的Zinoviev退化模型和有限元模型的有效性。利用此有限元模型分析了承受面内拉伸荷载的双边贴补修理复合材料层合板的失效模式,发现主要破坏模式为胶层的脱胶加速了母板中的纤维失效,导致结构最终失效。最后分析了主要修理参数对修理效果的影响,结果表明:增大补片尺寸可以明显提高修补结构的强度;当补片刚度与母板刚度相同时,修补效果较好;当补片厚度为母板厚度一半时,修补效果最好。

FAILURE MODE ANALYSIS AND DESIGN PARAMETERS SELECTION OF REPAIRED COMPOSITE LAMINATES

Zinoviev theory is one of the most popular stiffness degradation when performing progressive damage analysis of laminates,but it introduces many parameters which makes it difficult to understand and to be applied.Whereas,Zinoviev theory can only be used for 2D model.But,after being simplified and improved,Zinoviev theory can be less parameterd and suitable for 3D model.Based on this improved Zinoviev theory,combined with improved three-dimensional Hashin criterion,simulated the adhesive layers with INTER 205 element,progressive damage analysis of repaired composite laminates with a circular hole,which bears tensile load,have been conducted by ANSYS based on three-dimensional finite element.The results ofthree-dimensional finite element are in good agreement with those of experiments,and hence proved that the simplified and improved Zinoviev theory and the three-dimensional finite element is capable of simulating the progressive damage analysis of repaired composite laminates.The main failure mode of the repaired composite laminates and the impact of patch parameters on the strength of repaired laminates are discussed,and find out the main failure mode is fiber failure around the hole,which accelerates the failure of fiber in laminates.Increasing the size of patch can imporve the strength of repaired composites,and higher strength can be achieved by designing the stiffness of patch as same as laminates.The repair can be most effective when the patch thickness is half of laminates thickness.