【作者】 孙宝忠；

【导师】 顾伯洪；

【作者基本信息】 东华大学 ， 纺织材料与纺织品设计， 2004， 硕士

【摘要】 研制用于纤维束和纤维复合材料高应变率下力学性能测试的杆杆型冲击测试装置—分离式Hopkinson杆，描述该测试装置的硬件构成、信号采集和分析计算。通过这种测试装置，即可进行材料的动态压缩试验，也可进行材料的动态拉伸试验。 通过对碳纤维束的冲击拉伸试验表明，虽然碳纤维束的力学性能与应变率基本上是不相关的，即随着应变率的增大，碳纤维束的初始模量、破坏应力及其失效应变都变化不大，但碳纤维束的破坏断口与冲击拉伸实验的应变率密切相关。 首次对三维机织玻璃纤维复合材料进行了在高应变率下的面外压缩试验。实验结果表明，三维机织玻璃纤维复合材料在面外力学性能上是应变率相关的，随着应变率的增大，冲击压缩初始模量基本不变，但最大应力和最大应变都明显增加。 首次对多轴向经编玻璃纤维复合材料进行了高应变率下的面外压缩试验，实验结果表明，多轴向经编结构玻璃纤维复合材料在面外力学性能上是应变率相关的，随着应变率的增加，冲击压缩瞬时应力增加，最大应力和最大应变增加，同时初始模量也有增大的趋势。更多还原

【Abstract】 The bar-bar impact apparatus of split Hopkinson tensile/pressure bar for high strain rate tests of fiber reinforced composites is developed. The components of this apparatus, the data sampling method and software are introduced in details. This SHT/PB apparatus can be used for both compress tests and tensile tests of materials at high strain rate.Tensile tests of carbon filament yarn shows at high strain rate that the mechanical behavior of carbon fiber bundles are insensitive to strain rate, i.e., the failure stress strain and elastic modulus are not increased with the rising of strain-rate. However, the fractograph of carbon fiber is rate-dependent. The fractograph of carbon will become smooth from coarse as the strain rate increases.The compress tests on 3D woven glass-fiber composite have been carried out at high strain rates. The test results show that the out-of-plane compressive property of 3D woven composite are rate sensitive. The elastic modulus isn’t increased with the rising of strain-rate, however, the maximum compress stress and strain of 3D woven composite increase from 228Mpa to 272Mpa,from 15% to 20% as the strain rate increases from 2000/s to 3000/s. 3D woven glass-fiber composite is sensitive to strain rate.The compress tests on multiaxial multi-layer warp knit glass-fiber composite (MMWK) have also been carried out at high strain rates. The out-of-plane compressive property of multiaxial multi-layer warp knitglass-fiber composite are also rate sensitive. The maximum stress strain and elastic modulus of MMWK composite increase with the rising of strain rate. This shows that MMWK glass-fiber composite is sensitive to strain rate.更多还原