基于数字图像相关法的内聚力模型参数反演识别

Inversion identification of characteristic parameters of cohesive zone model basedona digital image correlation method

提出了一种基于Nelder-Mead(N-M)优化算法与响应面法的反演分析方法,用于获取粘接界面内聚力模型(CZM)参数.CZM通过用户自定义单元(UEL/ABAQUS)嵌入有限元模型,模拟单轴拉伸载荷下胶接双悬臂梁(DCB)界面的损伤断裂过程.采用数字图像相关(DIC)方法获取DCB实验中粘接界面的位移场.以实验获得的裂纹尖端局部位移信息为依据,结合有限元模拟相应工况下的位移信息,建立目标函数优化模型,对CZM参数进行反演识别.将反演的参数重新导入DCB有限元模型计算加载点的载荷—张开位移,模拟结果与实验结果吻合较好,表明了该基于数字图像相关的反演方法可以有效地表征内聚力模型参数,为其它材料或者模型参数的反演分析提供一个新的思路.

An inverse analysis was presented to determine cohesive parameters of flexible adhesive interfaces based on the Nelder-Mead （N-M） algorithm and response surface method. An optimization model was developed by using the measured local displacement around crack tip and the corresponding simulation results. The displacements were measured by the digital image correlation （DIC） method from a double cantilever beam （DCB） under mode I tensile loading. The simulations were conducted by using a cohesive zone model （CZM）implemented through the user subroutine UEL in ABAQUS. The predicted load-displacement curves based on the CZM and the model parameters from inverse analysis are in close agreement with the experimental results. The present work shows that the proposed inverse analysis method can effectively identify the parametei：s of cohesive zone model, which provides an effective way to the inversion identification of parameters for different material or models.