杨友喆, 李易, 周大兴, 陆新征, 孙海林. 板柱节点冲剪破坏后的精细有限元分析[J]. 工程力学, 2020, 37(6): 206-215. DOI: 10.6052/j.issn.1000-4750.2019.09.0494
引用本文: 杨友喆, 李易, 周大兴, 陆新征, 孙海林. 板柱节点冲剪破坏后的精细有限元分析[J]. 工程力学, 2020, 37(6): 206-215. DOI: 10.6052/j.issn.1000-4750.2019.09.0494
YANG You-zhe, LI Yi, ZHOU Da-xing, LU Xin-zheng, SUN Hai-lin. FINE FINITE ELEMENT ANALYSIS OF SLAB-COLUMN JOINTS AFTER PUNCHING SHEAR[J]. Engineering Mechanics, 2020, 37(6): 206-215. DOI: 10.6052/j.issn.1000-4750.2019.09.0494
Citation: YANG You-zhe, LI Yi, ZHOU Da-xing, LU Xin-zheng, SUN Hai-lin. FINE FINITE ELEMENT ANALYSIS OF SLAB-COLUMN JOINTS AFTER PUNCHING SHEAR[J]. Engineering Mechanics, 2020, 37(6): 206-215. DOI: 10.6052/j.issn.1000-4750.2019.09.0494

板柱节点冲剪破坏后的精细有限元分析

FINE FINITE ELEMENT ANALYSIS OF SLAB-COLUMN JOINTS AFTER PUNCHING SHEAR

  • 摘要: 按实际结构构造建立了板柱节点的精细有限元模型,采用实体单元和梁单元分别模拟混凝土和钢筋,采用生死单元技术模拟冲剪过程中混凝土开裂和冲剪后的钢筋断裂。3类典型冲剪试验的模拟验证表明该方法可以准确模拟冲剪和冲剪后的位移和承载力。基于该模型对约束节点的冲剪受力全过程进行了进一步的分析,结果表明:面内约束的板柱节点试验中,整体性钢筋和受弯钢筋对冲剪后承载力贡献为42%和58%;提高配筋率对节点冲剪前后的刚度均提升显著,而板厚增加仅对节点冲剪前的承载力和刚度有显著提升;欧美澳中四国规范在计算约束节点冲剪强度值时至少仍有36%的承载力储备,现有冲剪后承载力计算方法低估了负弯矩钢筋贡献,其冲剪后强度的计算值也都低于试验值。

     

    Abstract: The fine finite element models of slab-column joints were established according to the reinforcement detailing in real structures, in which the concrete and reinforcement were simulated by solid and beam elements, respectively. The element deactivation technique was adopted to simulate concrete cracking during the process of punching and the rupture of reinforcing bars after punching shear. The simulation method was validated via the comparison between the numerical and experimental results of three typical punching shear tests. The validation showed that the displacement and capacity of the punching and post-punching stages were accurately simulated by the developed method. Based on the numerical model, the analyses were further conducted to explore the mechanical behavior of the joints with in-plane constraints during a whole punching shear process. The results indicated that the contributions of integrity reinforcement and flexural reinforcement were 42% and 58%, respectively, to the post-punching resistances of the tested joints with in-plane constraints. The increase of reinforcement ratio leaded to the improvement of the stiffness of the joints at both punching and post-punching stages. On the other hand, increasing the slab thickness only significantly enhanced the capacity and stiffness of the joints before punching shear. That the redundant strength was at least 36% of the designed punching shear strength was found for the joints with in-plane constraints when using the calculation methods in European, American, Australian and Chinese codes. The predicted post-punching capacity calculated by the existing methods, in which the contribution of the flexural reinforcement was underestimated, was also lower than the tested capacity.

     

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