损伤单曲层压壳胶接修复结构力学性能测试与分析

EXPERIMENTAL INVESTIGATION ON LAMINATE SHELL STRUCTURES BONDED WITH COMPOSITE PATCHES

实际工程结构中存在大量的大曲率的曲面复合材料结构,因其特殊的外形和气动性要求,其复合材料补片胶接修理参数不能简单等同于平面复合材料结构。针对尺寸(长度L×曲率半径R×圆心角θ)为300mm×50mm×π/3rad、中心位置含20mm穿透型孔洞损伤的单曲层压壳结构,采用两种不同类型补片进行胶接修复试验,并对其力学性能进行测试与分析。结果表明:损伤孔的存在极大地降低了层压壳结构失效载荷、强度及模量,其损失率高达61%以上,而经胶接修复后其失效载荷、强度及模量可以得到明显改善,甚至恢复到完好程度;同时,采用楔形补片进行修复对改善修复结构中补片和损伤母板局部应力状态是十分有利的。

In actual engineering structures,there are a lot of curved composite structures with large curvature.Due to its special shape and aerodynamic requirements,the patch bonded repair parameters of them can not be simply equated with the planar composite structures. Aiming at the laminate shell structure,for which the size（ length× radius × central angle） is 300 mm × 50 mm × PI /3rad and contains a penetration hole of 20 mm diameter in the center,two types of composite patch were used to repair it. And then,the mechanism of the laminate shell structures was investigated experimentally. Generally,the hole in the laminate shell structure can reduce a great loss of the failure strength,and the loss rate can reach more than 61%; while the static mechanic properties of the bonded structures are significantly improved. The failure strength and static stiffness of the bonded structures could be the same as the perfect ones. Meanwhile,cuneal patch is beneficial to improve the stress condition of the patch and mother plate in repair structures.