摘要
对复合材料开口缝合补强结构进行了实验研究,测试了不同缝合参数(针距、行距、边距、单重和双重缝合)补强的含孔复合材料层板的破坏强度,研究了孔边应力集中和缝合补强对强度、破坏应变等力学性能参数的影响,分析讨论了孔边及邻近区域应变集中及应变分布的规律,结合破坏断面分析,探讨了不同缝合参数对应变集中及破坏机理的影响,研究结果表明:孔口缝合补强后,层板破坏强度和孔边局部刚度均有增大趋势,孔边产生了"缺口强化"现象;与未缝合情况相比,孔边应变衰减范围基本相同,而应变衰减程度不同;缝合设计参数(针距、行距、边距等)不同,孔边拉、压应变的转换点的位置也不同;不同的针距、行距以及边距对孔边应变集中都有很大影响。
Experiment studies were carried out on the effect of stitching reinforcement for composite laminates containing a circular hole. The effects of stitching parameters, such as stitching needle distance, row spacing, edge distance, single stitching or double stitching, etc. , were compared and analysed. The tensile strength and failure strain were measured for composite laminates containing a circular hole. The strain concentration and strain distribution regularity were investigated analytically and experimentally. By studing failure sections, the reinforcing effect and failure mechanisms were analysed and discussed for stitching on the edge of hole. The experi- mental results showed a distinct efficiency of stitching reinforcement for composite laminates containing a circular hole and gave a design method about stitching on the edge of hole.
From the current work, it is concluded that： stiffness and the failure strength of the composite laminates are somewhat increased. Reinforced by stitching, there exists a notch strengthing effect, which implies that the maximum strain at the hole edge becomes higher. Compared the stisehing reinforcement with unstitehing, the scope of strain deeling is roughly the same, but the level of strain declining obviously increase. There exist a transform point for tensile strain to compressing strain between 0° and 90° , that is εθ at the transform point. The transform point for single stitching is about θ = 56°, and for double stitching is about θ = 53°. Synthesizing the data and analysis, the single stitching 1 and the double stitching 1 are the better choices for the composite laminates when reinforced by stitching on the hole.
出处
《航空材料学报》
EI
CAS
CSCD
2008年第1期87-92,共6页
Journal of Aeronautical Materials
关键词
含孔复合材料层板
缝合补强
应变集中
破坏断面
composite laminates with holes
stitching reinforcement
strain concentration
failure sections
