杨红, 苏星宇, 赵银. 不同强度钢筋受压屈曲性能及材料本构模型[J]. 工程力学, 2023, 40(10): 112-128. DOI: 10.6052/j.issn.1000-4750.2022.01.0076
引用本文: 杨红, 苏星宇, 赵银. 不同强度钢筋受压屈曲性能及材料本构模型[J]. 工程力学, 2023, 40(10): 112-128. DOI: 10.6052/j.issn.1000-4750.2022.01.0076
YANG Hong, SU Xing-yu, ZHAO Yin. BUCKLING BEHAVIOR AND MATERIAL CONSTITUTIVE MODEL OF COMPRESSIVE STEEL BAR WITH DIFFERENT STRENGTH[J]. Engineering Mechanics, 2023, 40(10): 112-128. DOI: 10.6052/j.issn.1000-4750.2022.01.0076
Citation: YANG Hong, SU Xing-yu, ZHAO Yin. BUCKLING BEHAVIOR AND MATERIAL CONSTITUTIVE MODEL OF COMPRESSIVE STEEL BAR WITH DIFFERENT STRENGTH[J]. Engineering Mechanics, 2023, 40(10): 112-128. DOI: 10.6052/j.issn.1000-4750.2022.01.0076

不同强度钢筋受压屈曲性能及材料本构模型

BUCKLING BEHAVIOR AND MATERIAL CONSTITUTIVE MODEL OF COMPRESSIVE STEEL BAR WITH DIFFERENT STRENGTH

  • 摘要: 长径比和屈服强度是影响受压钢筋屈曲性能的主要参数,已有研究成果重点分析长径比的影响,关于屈服强度对钢筋屈曲后强度退化规律的系统性研究成果很少。该文完成了长径比分别为4.000、5.000、6.000、6.250、8.000、9.000、9.375、10.000、12.000和15.000的HRB400钢筋、HRB500钢筋试件的单调受压屈曲试验,测量了各屈曲钢筋试件的平均应力-平均应变 (\overline \sigma _\texts \text- \overline \varepsilon _\texts) 曲线和跨中横向屈曲位移。结合作者已完成的HRB600钢筋的相应试验结果,分析了屈服强度、长径比和屈曲方向对屈曲钢筋受压强度退化的影响,对比了D-M模型计算的\overline \sigma _\texts \text- \overline \varepsilon _\texts曲线与不同强度、长径比钢筋试件的屈曲受力性能差异。通过分析各类误差产生的原因,提出了可合理考虑长径比、屈服强度对屈曲效应影响的修正D-M模型。研究结果表明:由于不同强度钢筋的\varepsilon _\textu、\varepsilon _\textsh、f_\texty、f_\textu等力学性能参数不同,钢筋试件屈曲受力性能存在差异;较小长径比的钢筋受压屈曲后平均应力能继续提高,较大长径比的钢筋受压屈曲后无法达到屈服强度;不同长径比或屈服强度的钢筋试件屈曲方向存在差异;D-M模型的计算结果与三种强度钢筋的屈曲受力性能试验结果相比有明显误差;修正D-M模型可直接用于不同屈服强度钢筋,且能合理考虑长径比和屈服强度对屈曲钢筋\overline \sigma _\texts \text- \overline \varepsilon _\texts曲线的影响。

     

    Abstract: Slenderness ratio and yield strength are the main parameters affecting the buckling behavior of a compressed reinforcing steel bar; however, previous studies focus on the influence of slenderness ratio, there are few systematic research results related to the effect of yield strength on the strength degradation of buckled reinforcement. The monotonic compression tests considering buckling were thusly conducted on HRB400 and HRB500 reinforcement specimens with slenderness ratio of 4.000, 5.000, 6.000, 6.250, 8.000, 9.000, 9.375, 10.000, 12.000 and 15.000, respectively. The average stress-strain (\overline \sigma _\texts \text- \overline \varepsilon _\texts) curves and mid-span transverse displacements of buckled reinforcement specimens were measured. Combined with the corresponding test results of HRB600 reinforcement implemented by the author, the effects of yield strength, slenderness ratio and buckling direction on the compression strength degradation of buckled steel bars were analyzed. The difference between the \overline \sigma _\texts \text- \overline \varepsilon _\texts curves calculated by D-M model and the buckling behavior of steel bars with different yield strength and slenderness ratio were compared. By analyzing the causes of each kind of error, a modified D-M model was proposed, which can reasonably consider the effects of slenderness ratio and yield strength on buckling. The results show that there are differences in the buckling behavior of specimens with different strength due to the different mechanical properties of steel bar, such as \varepsilon _\textu, \varepsilon _\textsh, f_\texty, f_\textu, and etc. The compressive average stress of steel bar can be further improved after buckling if the slenderness ratio is small, while the buckled reinforcement with bigger slenderness ratio cannot reach the yield strength. The buckling directions of specimens with different slenderness ratio or yield strength are different. The calculation results of D-M model have obvious errors, compared with the experimental results of buckling behavior of specimens with three kinds of strength. The modified D-M model can be directly used for steel bar with different yield strength, and the effects of slenderness ratio and yield strength on the \overline \sigma _\texts \text- \overline \varepsilon _\texts curve of buckled steel bar can be reasonably rendered.

     

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