基于非线性渐进损伤模型的复合材料波纹梁耐撞性能研究

基于连续介质损伤力学,提出了一种包括层内和层间失效的非线性渐进损伤模型来预测复合材料波纹梁在轴向冲击下的失效行为。其中,层内损伤采用最大应力准则,并结合指数型损伤演化法则和刚度折减方法预测失效后的材料参数。层间损伤模型则采用了二次名义应力准则、基于混合模式能量的指数型损伤演化法则和黏性刚度折减方法建立。基于该模型,对典型的波纹梁结构参数和触发等对耐撞性的影响进行了研究。结果表明数值模拟结果与试验结果基本吻合,模型能够准确地模拟复合材料波纹梁在冲击过程中出现的分层、纤维和基体破坏等失效模式。波纹梁在破坏过程中吸收的能量、比吸能和载荷峰值随层数不断递增,降低高度和减小触发结构的截面面积均会降低载荷峰值。

Crashworthiness of composite corrugated beam based on nonlinear progressive damage model

Based on continuum damage mechanics,a nonlinear progressive damage model including intra-and inter-laminar failures was presented to predict the failure behavior of composite corrugated beam under the axial crushing.The maximum stress criterion combined with exponential damage evolution laws and stiffness discount method were adopted to predict the material parameters of intra-laminar damage.The inter-laminar damage model was modeled by a quadratic nominal stress criterion,an exponential damage evolution law based on the mixed-mode energy and cohesive stiffness discount method.Based on this model,the effect of triggers and the typical parameters of corrugated beam structures on crashworthiness were investigated.The results of numerical simulation show basic agreement with the experimental data.The failure modes of delamination,fiber and matrix damage that appeared in the impact process of composite corrugated beam can be simulated accurately.During the damage of corrugated beam,absorbed energy,specific energy absorption as well as the peak load are the increasing function with respect to the layers.In addition,the peak load decreases with the decreasing of height and trigger-sectional area.