Study on dynamic mechanical behavior of Q460JSC and HQ600 high strength steel
Study on dynamic mechanical behavior of Q460JSC and HQ600 high strength steel
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Q460JSC和HQ600高强钢动态力学行为研究
DOI：
10.1016/j.jcsr.2020.106232
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发表时间：
2020-10-01
影响因子：
4.1
通讯作者：
Tang, Yu
中科院分区：
文献类型：
--
作者：
Liu, Xiyue;He, Zhiyang;Tang, Yu
高强钢已逐步应用于实际工程中，取得了良好的经济效益和社会效益。由于恐怖袭击和意外爆炸的威胁，高强度钢结构需要具有很高的抗爆性能。然而，高强度钢在高应变率下的力学性能和本构方程的研究还不够充分。高强钢结构抗爆性能的研究缺乏材料模型和本构参数。因此，本文研究了Q460 JSC和HQ 600高强钢的准静态和动态力学性能。在0.00025 ~ 5000 s（-1）的应变速率范围内进行了一系列准静态拉伸、高速拉伸和SHTB试验，获得了材料在不同应变速率下的力学性能。结合LS-DYNA有限元模拟，采用逆外推法处理颈缩后试样的应变硬化关系，得到不同应变速率下的真应力-应变曲线。分析了应变速率对材料强度和塑性的影响。采用Ludwik准则和修正的Johnson-Cook模型分别拟合了这两种高强度钢的准静态和动态本构参数。结果表明，这两种高强度钢的屈服强度、极限强度和断裂应变均随应变速率的增加而增加，但均匀延伸率对应变速率不敏感。在10（3）应变速率范围内，强度变化不明显。逆外推法处理颈缩后的真应力-应变曲线是有效的，通过不断优化应变硬化指数可以得到更精确的结果。改进的Ludwik准则和新的Johnson-Cook模型修正公式能很好地描述这两种高强钢材料在10（-3）s（-1）~ 10（3）s（-1）范围内的应力应变关系，为高强钢结构抗爆性能的研究提供了依据。(C)2020由Elsevier Ltd.出版
High-strength steel has been gradually applied in practical engineering and achieved good economic and social benefits. Due to the threat of terrorist attacks and accidental explosions, high-strength steel structures need to have high blast resistance. However, the studies on the mechanical properties and constitutive equations of high-strength steels under high strain rate are insufficient. The research on the anti-explosion properties of high-strength steel structures lacks material models and constitutive parameters. Therefore, this paper investigated the quasi-static and dynamic mechanical properties of Q460JSC and HQ600 high strength steels. A series of quasi-static tensile, high-speed tensile and SHTB tests were conducted to obtain the material properties under different strain rate in the range of 0.00025 s(-1) to 5000 s(-1). Combined with finite element simulation by LS-DYNA, the strain hardening relationship of specimens after necking was treated by inverse extrapolation method, and the true stress-strain curves at different strain rates were obtained. The effects of strain rate on materials strength and plasticity were analyzed. The quasi-static and dynamic constitutive parameters of these two high strength steels were fitted by Ludwik criterion and modified Johnson-Cook model, respectively. The results show that the yield strength, ultimate strength and fracture strain of these two kinds of high strength steels all increase with the increase of strain rate, but the uniform elongation is not sensitive to strain rate. The change of strength is not obvious in the strain rate range of 10(3). The inverse extrapolation method is effective in dealing with the true stress-strain curve after necking, and more accurate results can be obtained by continuously optimizing the strain hardening index. The improved Ludwik criterion and the new Johnson-Cook model correction formula can well describe the stress-strain relationship of these two high-strength steel materials in the range of 10(-3) s(-1) to 10(3) s(-1), which provide basis for the investigation on anti-explosion properties of high-strength steel structures. (C) 2020 Published by Elsevier Ltd.