熊学玉, 谢一凡, 姚刚峰. 基于修正的软化拉压杆模型的RC框架边节点受剪性能研究[J]. 工程力学, 2022, 39(6): 55-71. DOI: 10.6052/j.issn.1000-4750.2021.03.0192
引用本文: 熊学玉, 谢一凡, 姚刚峰. 基于修正的软化拉压杆模型的RC框架边节点受剪性能研究[J]. 工程力学, 2022, 39(6): 55-71. DOI: 10.6052/j.issn.1000-4750.2021.03.0192
XIONG Xue-yu, XIE Yi-fan, YAO Gang-feng. STUDY ON SHEAR BEHAVIOUR OF EXTERIOR REINFORCED CONCRETE BEAM-COLUMN JOINTS BASED ON MODIFIED SOFTENED STRUT AND TIE MODEL[J]. Engineering Mechanics, 2022, 39(6): 55-71. DOI: 10.6052/j.issn.1000-4750.2021.03.0192
Citation: XIONG Xue-yu, XIE Yi-fan, YAO Gang-feng. STUDY ON SHEAR BEHAVIOUR OF EXTERIOR REINFORCED CONCRETE BEAM-COLUMN JOINTS BASED ON MODIFIED SOFTENED STRUT AND TIE MODEL[J]. Engineering Mechanics, 2022, 39(6): 55-71. DOI: 10.6052/j.issn.1000-4750.2021.03.0192

基于修正的软化拉压杆模型的RC框架边节点受剪性能研究

STUDY ON SHEAR BEHAVIOUR OF EXTERIOR REINFORCED CONCRETE BEAM-COLUMN JOINTS BASED ON MODIFIED SOFTENED STRUT AND TIE MODEL

  • 摘要: 在软化拉压杆模型(Softened strut and tie model, SSTM)基础上,针对边节点受力特点,建议采用更准确的混凝土斜压杆倾角计算公式,并基于44个RC框架边节点核心区剪应力-剪应变骨架曲线的试验数据,拟合了软化混凝土本构曲线,提出修正的软化拉压杆模型(Modified softened strut and tie model, MSSTM)。使用传统SSTM模型、约束斜压杆模型和MSSTM模型分别对91个边节点受剪承载力(其中56个发生节点核心区剪切破坏)、26个边节点核心区剪应力-剪应变骨架曲线进行计算。结果表明:MSSTM模型对受剪承载力以及剪应力-剪应变骨架曲线的预测效果整体优于SSTM模型和约束斜压杆模型。就承载力而言,SSTM模型、约束斜压杆模型和MSSTM模型的计算值与试验值之比的均值分别为1.028、1.203和0.995,变异系数分别为0.230、0.273和0.164。MSSTM模型计算结果更准确且离散性更小。此外,MSSTM模型可较好预测应力-应变曲线上的特征参数,尤其是峰值剪应力和开裂刚度。两者计算与试验结果比值的均值分别为1.14和1.02。

     

    Abstract: Based on the softened strut and tie model, a more precise equation for calculating the angle of diagonal concrete strut inclination is suggested based on the strain distribution of exterior beam column joints, and an empirical softened constitutive model of concrete is given on the basis of experimental data from 44 exterior RC beam column joints. Thus the modified softened strut and tie model is derived. The shear strength of 91 exterior joints (joint shear failure occurred on 56 of them) and shear stress-strain curves of 26 exterior joints are calculated by SSTM, diagonal compression strut model (DCSM) and MSSTM, respectively. The results indicate that MSSTM is more accurate on predicting the shear strength and the shear stress-strain curves compared with SSTM and DCSM. The average ratios of calculated to measured shear strength of SSTM, DCSM and MSSTM are 1.028, 1.203 and 0.995 respectively, and the coefficient of variation are 0.230, 0.273 and 0.164 respectively. The accuracy of MSSTM prediction is better and the variability is significantly reduced. Also, MSSTM can predict the key points of shear stress-strain curves well, particularly in terms of peak shear stress and initial stiffness. The average ratios of calculated to measured peak shear stress and initial stiffness are 1.14 and 1.02 respectively.

     

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