论文部分内容阅读
本文利用岛津试验机和自行研制的冲击拉伸试验装置,对体积含量为10％的SiC颗粒增强铝基复合材料进行了准静态的拉伸试验、冲击拉伸试验和冲击拉伸加卸载试验,获得了复合材料在应变率为0.002s~(-1)～1000s~(-1)范围内从弹塑性变形直至断裂的完整应力应变曲线。试验结果表明,随着应变速率的提高,复合材料的屈服应力,拉伸强度以及破坏应变均相应提高,具有明显的应变率强化效应和高速韧性现象;同时,由于冲击拉伸试验过程中热力耦合效应的影响,准静态加载下复合材料的应力指数与冲击拉伸加载下复合材料的应力指数相比降低了17.8％;在用冲击拉伸复元试验解耦出热力耦合效应的影响后,材料的静、动态等温应力应变曲线具有相同的应变硬化规律。最后,根据复合材料在不同应变率下的试验结果和Eshelby’s等效夹杂理论,本文建立了一个计及应变率强化效应的弹塑性自洽模型,模型拟合结果与试验结果吻合得很好。
In this paper, Shimadzu test machine and self-developed impact tensile test device, the volume content of 10% SiC particle reinforced aluminum matrix composites were quasi-static tensile test, impact tensile test and impact tensile loading and unloading test , A complete stress-strain curve of the composite material from elastic-plastic deformation until fracture was obtained in the strain rate range of 0.002s -1 to 1000s -1. The experimental results show that with the increase of strain rate, the yield stress, tensile strength and failure strain of the composites increase correspondingly, with obvious strain rate strengthening effect and high-speed toughness phenomenon. At the same time, due to the thermal coupling during the impact tensile test Effect, the stress exponent of the composites decreases by 17.8% under the quasi-static loading compared with the stress exponent of the composites under impact loading. After decoupling the influence of the thermal coupling effect by the impact tensile compaction test, Static and dynamic isothermal stress-strain curves have the same strain hardening law. Finally, according to the test results of composite materials at different strain rates and the Eshelby’s equivalent inclusion theory, an elasto-plastic self-consistent model considering the strain rate enhancement effect is established. The model fitting results are in good agreement with the experimental results.