Strain rate and temperature sensitivity and constitutive model of YB-2 of aeronautical acrylic polymer
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摘要: 为了理解和评价YB-2航空有机玻璃在极端环境下的动态力学性能,采用电子万能试验机和分离式Hopkinson压杆对YB-2航空有机玻璃在218~373 K温度范围、10-3~3 000 s-1应变率范围内的压缩力学行为进行了研究,得到了材料的应力应变曲线。结果表明:随着温度的升高,材料的流动应力逐渐减小而破坏应变呈现增大的趋势;温度相同时,材料的流动应力随应变率的增加而增大,破坏应变随应变率的增加而减小。随着应变率的提高,材料的应变软化效应更加剧烈。基于朱-王-唐(ZWT)本构模型,得到了考虑温度效应的本构参数。结果显示,在8%应变范围内,改进的考虑温度效应的本构模型可以较为理想地表征该材料的应力应变响应。
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关键词:
- 固体力学 /
- 本构模型 /
- Hopkinson压杆 /
- YB-2航空有机玻璃 /
- 应变率 /
- 温度效应
Abstract: To investigate dynamic mechanical performances of YB-2 aeronautical polymer used as the aircraft windshield in extreme mechanical environments, we performed uniaxial compression tests on cylindrical samples, using an Instron servo hydraulic axial testing machine and the compression Hopkinson bar at strain rates ranging from 10-3 s-1 to 3 000 s-1 and at initial temperatures ranging from 218 K to 373 K, and obtained the true strain stress curves. Our results indicate that the Young's modulus and flow stress decrease as the temperature increases, while the fracture strain tends to increase as the temperature increases. At the same temperature, it was found the flow stress increases with the rising strain rate, and the strain softening effect was also observed to be more acute with the increasing strain rates. Based on the ZWT model, the parameters of a prediction model that takes temperature into consideration has been gained. The predictions are in good agreement with experimental results in the strain range of 8%.-
Key words:
- solid mechanics /
- constitutive model /
- Hopkinson bar /
- YB-2 aeronautical polymer /
- strain rate /
- temperature
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表 1 温度影响项中各系数的方差和置信区间
Table 1. Variances and confidence intervals of the coefficients for thermo-item
参数 方差 置信区间 a 0.381 131 (0.527 425, 1.273 1) b 0.009 826 (-0.235 72, -0.103 88) c 0.000 295 (-0.004 56, -0.003 54) -
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