Analysis of Compressive Strength of Composite Materials after Impact

开发了一种嵌入式通宽分层（ETWD）夹层柱试件，并将其应用于后屈曲分层的表征。基于弹性梁理论和有限元分析对后屈曲分层进行了理论分析。研究了混合模式载荷对分层生长临界条件的影响，并基于线弹性断裂力学计算了临界应力。实验研究了脱层板局部屈曲的发生、脱层生长和扩展的临界载荷。将分析结果与实验结果进行了比较，提出了一种基于复合材料层间I型和II型断裂韧性的损伤容限估计方法。

An embedded through-width delamination (ETWD) sandwich column specimen has been developed and applied to characterization of the post-buckled delamination. Theoretical analysis based on the elastic beam theory and finite element analysis have been carried out in order to investigate the post-buckled delamination. The effect of the mixed mode loading on the critical condition of delamination growth has been also examined and the critical stress is calculated based on the linear elastic fracture mechanics. Onset of the local buckling in the delaminated laminate, the critical load of the delamination growth and propagation of delamination have been investigated experimentally. The analytical results have been compared with the experimental results, and a damage tolerance estimation method has been proposed by using mode I and II interlaminar fracture toughness of composite laminate.