张世顺, 田径, 陈东, 曾卓, 聂雪飞. 预制节段UHPC梁接缝抗剪性能的有限元模拟[J]. 工程力学, 2023, 40(6): 85-98, 256. DOI: 10.6052/j.issn.1000-4750.2021.11.0876
引用本文: 张世顺, 田径, 陈东, 曾卓, 聂雪飞. 预制节段UHPC梁接缝抗剪性能的有限元模拟[J]. 工程力学, 2023, 40(6): 85-98, 256. DOI: 10.6052/j.issn.1000-4750.2021.11.0876
ZHANG Shi-shun, TIAN Jing, CHEN Dong, ZENG Zhuo, NIE Xue-fei. FINITE ELEMENT MODELLING OF THE SHEAR BEHAVIOR OF JOINTS IN PRECAST SEGMENTAL UHPC BRIDGE GIRDERS[J]. Engineering Mechanics, 2023, 40(6): 85-98, 256. DOI: 10.6052/j.issn.1000-4750.2021.11.0876
Citation: ZHANG Shi-shun, TIAN Jing, CHEN Dong, ZENG Zhuo, NIE Xue-fei. FINITE ELEMENT MODELLING OF THE SHEAR BEHAVIOR OF JOINTS IN PRECAST SEGMENTAL UHPC BRIDGE GIRDERS[J]. Engineering Mechanics, 2023, 40(6): 85-98, 256. DOI: 10.6052/j.issn.1000-4750.2021.11.0876

预制节段UHPC梁接缝抗剪性能的有限元模拟

FINITE ELEMENT MODELLING OF THE SHEAR BEHAVIOR OF JOINTS IN PRECAST SEGMENTAL UHPC BRIDGE GIRDERS

  • 摘要: 该文采用有限元软件ABAQUS对预制节段超高性能混凝土(UHPC)梁剪力键接缝的抗剪性能进行了三维精细有限元模拟。模型中同时考虑了材料非线性、几何非线性以及UHPC材料的塑性损伤,模拟得到的荷载-滑移曲线和破坏模态等均与试验结果吻合良好。采用经过验证的有限元模型对剪力键接缝的抗剪性能进行了数值参数分析,结果表明:接缝的抗剪承载力及其对应的滑移随着所施加的侧向应力或UHPC强度的增大而增大,但UHPC抗压强度对抗剪承载力的影响大于UHPC抗拉强度,而且UHPC的抗拉压强度之间无固定的相关规律,因此对于UHPC接缝抗剪承载力的计算应分别考虑抗拉强度与抗压强度的影响;由于剪应力分布的不均匀性,抗剪承载力的计算还应考虑多键块的强度折减效应。此外,对剪力键接缝构造的参数分析结果表明:当键块的宽度和总高度相同时,接缝抗剪承载力随着键块相对高度的减小而增大,但当键块相对高度小于1/2时,接缝的抗剪承载力基本保持不变;当键块总面积以及键块数量相同时,多个键块之间的协同工作能力随键块竖向间距的增大而变强;键块深度对接缝抗剪承载力的影响不大。与目前被广泛采用的普通混凝土接缝抗剪承载力的计算公式对比,有限元的预测值明显小于计算公式的预测值,且偏差随着侧向应力的增大而增大,因此有必要针对UHPC剪力键接缝提出新的抗剪承载力计算式。

     

    Abstract: The finite element (FE) software ABAQUS was used to establish a three-dimensional fine FE model for the shear behavior of the keyed joints in the precast segmental ultra-high-performance concrete (UHPC) bridge girders. Material nonlinearity, geometric nonlinearity, and plastic damage of UHPC material were carefully considered in the model. The predicted load-slip curves and failure modes of the joints from the FE model are in a good agreement with the experimental results. The verified FE model was then used to analyze the shear behavior of the keyed joints. The results showed that: the shear capacity of the joints and its corresponding slip increase with the increase of the applied confining pressure or UHPC strength, but the influence of UHPC compressive strength on the shear capacity of the keyed joint is greater than that of UHPC tensile strength; in addition, there is no fixed correlation discipline between UHPC tensile strength and compressive strength, and thus for the calculation of the shear capacity of UHPC joints, the effects of UHPC tensile strength and compressive strength should be considered separately; due to the inhomogeneity of the shear stress distribution, the calculation of the shear capacity of the keyed joint should also consider the strength reduction effect of the multi-keys. In addition, the results of parametric analysis on the layout of keyed joints showed that: when the width and total height of the keys have the same dimension, the shear capacity of the joint increases with the decrease of the relative height of keys; however, when the relative height of keys is less than 1/2, the shear capacity of the joint remains basically unchanged; when the total area and number of keys are the same, the cooperative work ability between multiple keys becomes stronger with the increase of the key spacing; the depth of the keys has little effect on the shear capacity of the joint. Compared with the currently widely used formula for calculating the shear capacity of ordinary concrete joints, the FE predicted shear capacity of UHPC keyed joint is significantly smaller than the predicted result from the calculation formula, and the deviation increases with the increase of confining pressure. Therefore, it is necessary to propose a new calculation formula for the shear capacity of UHPC keyed joints.

     

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