| 摘要: |
| 对高强度建筑钢筋HRB500在应变率（ε·）为49~590s-1下的力学行为进行了试验研究，并以钢筋力学性能特征值和Johnson Cook模型(J C模型)为基础分别建立了两类HRB500钢筋动力本构模型.结果表明：HRB500钢筋的力学性能呈应变率相关性.随着应变率的增大，钢筋的屈服强度、极限强度以及极限强度对应的应变提高；在相同应变率条件下，钢筋屈服强度动力提高系数大于极限强度动力提高系数.相比较低强度的HPB235，HRB335以及HRB400钢筋，HRB500钢筋的应变率敏感性稍弱.建议以钢筋力学性能特征值为基础建立的动力本构模型可用于描述30×10-4s-1≤ε·≤500s-1时HRB500钢筋的力学行为，而以J C模型为基础建立的动力本构模型仅用于描述10s-1≤ε·≤500s-1时HRB500钢筋的力学行为. |
| 关键词: HRB500钢筋 本构模型 应变率 动力提高系数 |
| DOI：103969/j.issn1007 9629201404006 |
| 分类号: |
| 基金项目:国家高技术研究发展计划（863计划）项目（2012AA050903） |
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| Dynamic Constitutive Models for High Strength Reinforcing Steel Bar HRB500 |
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LIN Feng, DONG Yu, GU Xianglin
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Department of Building Engineering, Tongji University, Shanghai 200092, China
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| Abstract: |
| Dynamic mechanical behaviors of high strength reinforcing steel bar HRB500 were experimentally studied over the range of strain rates from 49s-1 to 590s-1. Dynamic constitutive models based on characteristic values of mechanical performance and Johnson Cook(J C) model were proposed to describe the dynamic mechanical behaviors of steel bar HRB500. It is found that the mechanical behavior of steel bar HRB500 is strain rate dependent. The yield strength, the ultimate strength as well as the strain corresponding to the ultimate strength increase as the strain rate increases. The dynamic increase factor for yield strength is more appreciable than that for ultimate strength at the same strain rate. However, the strain rate sensitivity of steel bar HRB500 is slightly weak in comparison with those of low strength steel bars, such as HPB235, HRB335 and HRB400. It is suggested that dynamic constitutive model based on characteristic values of mechanical performance can be used to describe the dynamic mechanical behaviors of steel bar HRB500 over the range of strain rates from 30×10-4s-1 to 500s-1, and the dynamic constitutive model based on J C model can be used to describe the dynamic mechanical behaviors of steel bar HRB500 over the range of strain rates from 10s-1 to 500s-1. |
| Key words: steel bar HRB500 constitutive model strain rate dynamic increase factor |
