复合材料层合板低速冲击后剩余压缩强度研究

应用有限元显式算法计算层合板冲击后压缩强度(CAI值)。建立实体单元与cohesive界面单元相结合的层合板有限元分析模型。首先进行层合板受离面低速冲击中损伤过程的数值模拟,再以该步分析结果(损伤状态)作为初始损伤,进行面内压缩下层合板破坏过程数值模拟。从而实现了层合板从冲击损伤到冲击后压缩破坏的全过程分析。模型应用面内和层间损伤逐渐累积的算法。通过不同加载速率下的分析,考察了显式算法在准静态CAI计算中的可用性。冲击损伤特征、冲击后压缩破坏特征及CAI的计算值与试验结果有良好的一致性,表明文中所采用的模型、算法与损伤处理方法是合理的。

Effectively Calculating Residual Compressive Strength of Composite Laminate after Impact (CAI)

The explicit finite element model was established using the solid elements and interfacial cohesive elements.A two-step calculation procedure was established.Sections 1 through 3 of the full paper explain our method of calculation mentioned in the title,which we believe is effective and whose core consists of:(1) the out of plane low-velocity impact process was simulated first;the results of the first step,namely the state of the damages and deformation,were taken as the input for the second step to simulate the in-plane compression,until the collapse of the laminate;the strength criterion and a stiffness degradation scheme were utilized to characterize various types of the in-plane damages;the initiation and propagation of the delamination damage was estimated with the cohesive elements according to the failure criteria and critical energy release rate criterion respectively;(2) the usefulness of the explicit solution algorithm in dealing with the quasi-static procedure of the in-plane compression was investigated by examining the effect of different velocities of the compression loading on the CAI values.The simulation results for the impact damages and the compression-after impact damages,presented in Figs.3 through 7 excepting 5 and Tables 3 through 5,and their analysis show preliminarily that they are indeed in fairly good agreement with the experimental ones.