含穿透损伤泡沫夹层结构的修补及拉伸性能

建立了复合材料泡沫夹层结构含穿透损伤挖补维修的三维有限元模型,对其在单、双向拉伸载荷作用下进行了有限元分析,根据各铺层的材料主方向的应力分布,采用最大应力强度准则计算了挖补维修前后结构的单、双向拉伸强度。结果表明:单向拉伸载荷状态下,维修后结构强度恢复系数为88.1%,初始损伤为面内剪切失效;双向拉伸载荷状态下,维修后结构强度恢复系数为97.6%,初始损伤为纤维拉伸断裂。最佳表面额外贴补层数量为1至2层,过多贴补层会导致局部应力集中,使维修后结构强度下降。

Repair and Tensile Properties Analysis of Foam Core Sandwich Panel With Penetrating Damage

The three-dimensional finite element model of foam core sandwich panel with penetrating defects is established.Finite element analysis is carried out on this model under the uniaxial and twin-axial tensile loading.According to the stress distributions of material principle direction of the scarf-patch repaired panel,the uniaxial and twin-axial tensile strength of the intact and scarf-patch repaired panels are calculated based on the strength criterion of maximum stress.It is shown that under the uniaxial tensile loading,the strength recovery coefficient of the repaired panel is 88.1%,and the initial damage mode is matrix shear failure.Under the twin-axial tensile loading,the strength recovery coefficient of the repaired panel is 97.6%,and the initial damage mode is the fracture of the reinforcing fiber.The optimum number of surface patch is one or two.More surface patches cause local stress concentration and thus strength reduction of the panel occurs.