高温高应变率下G550冷弯钢的动态力学行为  

Dynamic Mechanical Behavior of G550 Cold-Formed Steel under High Temperature and High Strain Rate

作　　者：严吉涛 陈文飞 张浩[1,2] 尤建 史超铭 蒋昊成 朱珏[1,2] YAN Jitao;CHEN Wenfei;ZHANG Hao;YOU Jian;SHI Chaoming;JIANG Haocheng;ZHU Jue(Zhejiang Provincial Engineering Research Center for the Safety of Pressure Vessel and Pipeline,Ningbo University,Ningbo 315211,Zhejiang,China;Key Laboratory of Impact and Safety Engineering,Ministry of Education,Ningbo University,Ningbo 315211,Zhejiang,China;Ningbo Special Equipment Inspection and Research Institute,Ningbo 315211,Zhejiang,China)

机构地区：[1]宁波大学压力容器与管道安全浙江省工程研究中心,浙江宁波315211 [2]宁波大学冲击与安全工程教育部重点实验室,浙江宁波315211 [3]宁波市特种设备检验研究院,浙江宁波315211

出　　处：《高压物理学报》2023年第2期30-40,共11页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(11972203,11572162)。

摘　　要：为研究G550冷弯钢在高温和高应变率下的动态力学性能,采用高温同步控制霍普金森拉杆装置,开展了不同温度下的高应变率拉伸试验,并在高速液压拉伸试验机上进行了室温下的中应变率拉伸试验。通过获得的应力-应变曲线,得到了材料的本构模型,结合微观形貌分析,探究了温度和应变率对流变应力的影响。结果表明:G550冷弯钢具有明显的应变率强化和温度软化效应。在特定的高应变率范围内(1000~1500 s-1),温度对流变应力的影响大于应变率。基于温度软化系数随温度变化的特征,提出了G550冷弯钢的修正Johnson-Cook本构模型。该模型可以较好地描述G550冷弯钢在高温和高应变率下的动态力学行为,从而为G550冷弯钢在高温、爆炸冲击相关的有限元仿真提供参考。To study the dynamic mechanical properties of G550 cold-formed steel under high temperature and high strain rate,high-temperature synchronous controlled dynamic loading device(split Hopkinson tensile bar)was implemented.The medium strain rate tensile tests were also conducted with the high-speed hydraulic tensile testing machine.The constitutive model and the influence of temperature and strain rate on the flow stress were built and explored through the stress-strain curve and the microscopic analysis.The results show that G550 cold-formed steel has significant strain rate strengthening and temperature softening effects.In the specific high strain rate range(1000−1500 s−1),the influence of temperature on the flow stress is more significant than that of strain rate.Then,a modified Johnson-Cook constitutive model of G550 coldformed steel was proposed according to the temperature softening coefficient.This model can better describe the dynamic mechanical behavior of G550 cold-formed steel under high temperature and high strain rate,and can contribute to the finite element simulation of G550 cold-formed steel under high temperature and explosion impact.

关 键 词：G550冷弯钢 高温 高应变率 本构模型 

分 类 号：O347[理学—固体力学] TG142[理学—力学]