平纹机织玻璃纤维增强复合材料面内压缩力学行为及破坏机制
In-plane compressive mechanics behavior and failure mechanism for SW200/ LWR-2 glass-woven composite
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摘要: 为了研究平纹机织玻璃纤维复合材料SW200/LWR-2 的面内压缩力学性能并建立其本构模型, 对其进行了应变率为0. 001 s-1 、0. 1 s-1 、500 s-1 , 温度从- 55 ℃到100 ℃范围内的面内压缩实验研究。动态压缩实验在SHPB 装置上进行, 通过波形整形器实现了恒定应变率加载, 且经过验证试样两端应力平衡。实验结果表明, SW200/ LWR-2 复合材料性能具有明显的应变率敏感性及温度敏感性, 其强度随着应变率的升高而增大, 随着温度的升高而减小。对破坏后试样进行宏观及微观观察发现, 准静态加载时试样为剪切破坏, 伴随大量纤维束内脱粘和纤维拔出; 动态加载时试样为剪切破坏与分层破坏并存, 并出现大量碎屑, 纤维束为整束剪断, 束内脱粘受到抑制。根据损伤力学理论, 建立了SW200/ LWR-2 复合材料应变率及温度相关面内压缩损伤统计本构模型, 本构模型结果与实验结果吻合较好。Abstract: In order to investigate the in-plane compressive mechanics behavior of the SW200/LWR-2 glass-woven composite and establish the constitutive model, the in-plane compressive tests for this material were performed with the strain rates of 0. 001 s -1, 0. 1 s-1, 500 s-1 and a temperature range from - 55 ℃ to 100 ℃. The dynamic compressive tests were carried out using the SHPB technique, a constant loading strain rate was achieved with a waveform shaper, and it is also verified that the stresses on the two sides of the specimen are in balance. Experimental results show that the mechanical properties of the SW200/LWR-2 glass-woven composite are sensitive to the strain rate and temperature; its strength increases with increasing strain rate, and decreasing temperature. Macro- and microscopical observation reveals that the samples under quasi-static loading presents hearing failure mode , and the fibre bundles of the samples are extensively debonded and pulled out. The samples under dynamic loading present shearing and delamination modes with lots of rags, and at the same time the debonding of the fibre bundles is restrained. Finally, based on the damage mechanics theory, a compressive constitutive model including the strain rate and temperature effects for the SW200/LWR-2 composite is established, and the modeling results have good agreement with the experimental results.