复合材料层合板面内渐进损伤分析的CDM模型

CDM MODEL FOR INTRALAMINAR PROGRESSIVE DAMAGE ANALYSIS OF COMPOSITE LAMINATES

基于连续介质损伤力学,提出了一个预测复合材料层合板面内渐进损伤分析的模型,它包括损伤表征、损伤判定和损伤演化3部分.模型能够区分纤维拉伸断裂、纤维压缩断裂、纤维间拉伸损伤和纤维间压缩损伤4种损伤模式,定义了与4个损伤模式对应的损伤状态变量,导出了材料主轴系下损伤前后材料本构之间的关系.损伤起始采用Puck准则判定,损伤演化由特征长度内应变能释放密度控制.假定材料服从线性应变软化行为,建立了损伤状态变量关于断裂面上等效应变的渐进损伤演化法则.模型涵盖了复合材料面内损伤起始、演化直至最终失效的全过程.完成了含孔[45/0/-45/90]2S层合板在拉伸和压缩载荷下失效分析,结果表明该模型能合理进行层合板的强度预测和损伤失效分析.

Based on continuum damage mechanics （CDM）, a model was proposed for predicting intralaminar progressive damage of composite laminates, including damage description, damage model judgment and damage evolution. Four different damage modes existent within lamina, namely, fiber tension fracture （FFT）, fiber compression fracture （FFC）, inter fiber tension fracture （IFFT） and inter fiber compression fracture （IFFC）, were considered, and damage state variables corresponding to these four modes were also defined. Material constitutive relationship being in the damaged states in the material principal axes was derived compared to that of undamaged states. The onset of the damage was estimated with Puck＇s criteria and the evolution of the damage was controlled by the strain energy release density within the characteristic length. Assuming that the material was exhibited linear strain-softening behavior, a new damage evolution law associating damage state variables with equivalent strain on fracture plane was established in this paper. The proposed model can predict damage initiation, damage evolution and final failure of composite laminates. Failure analyses of [45/0/-45/9012S notched laminates under tension and compression were performed withthe present model and showed that it is capable to predict the strength of the composite laminate and analyze the failure process.