小尺寸试件层合板低速冲击后的剩余压缩强度

使用一种小尺寸试件试验方法来测量复合材料层合板低速冲击后的剩余压缩强度(CAI),以便减少试验费用,降低材料研制成本和周期。在试验研究的基础上,建立了复合材料低速冲击后剩余压缩强度估算的一种软化夹杂模型。该模型将冲击损伤等效成圆形低刚度的夹杂,用8节点等参元分析层合板的应力应变状态,以点应力准则为压缩破坏判据。理论分析结果与试验对比显示,该模型简单有效。

POST-IMPACT COMPRESSIVE STRENGTH OF SMALL COMPOSITE LAMINATE SPECIMENS

A miniature post impact compression test was used to study the technique for composite testing with a view to reducing the cost of testing materials. This test method can be used in a material developing phase. Based on experimental studies, a reduced stiffness inclusion model was developed to predict the residual compressive strength of composite laminates after the low velocity impact. In this model the damage was considered as a soft zone of the material. The damage zone was assumed to be circular. A finite element code with the 8-node 2D isoparametric element was programmed to compute the stress distributions. The point stress criterion was used to determine whether the post-impact laminates are compressed to failure or not. Good agreement between predicted residual compressive strengths and experimental results is obtained.