吴晨伟, 薛建阳, 宋德军, 张家赫. 歪闪平身科斗栱轴压性能试验研究及有限元分析[J]. 工程力学. DOI: 10.6052/j.issn.1000-4750.2023.01.0061
引用本文: 吴晨伟, 薛建阳, 宋德军, 张家赫. 歪闪平身科斗栱轴压性能试验研究及有限元分析[J]. 工程力学. DOI: 10.6052/j.issn.1000-4750.2023.01.0061
WU Chen-wei, XUE Jian-yang, SONG De-jun, ZHANG Jia-he. EXPERIMENTAL RESEARCH AND FINITE ELEMENT ANALYSIS ON AXIAL COMPRESSION PERFORMANCE OF INCLINED PINGSHENKE DOU-GONG BRACKETS[J]. Engineering Mechanics. DOI: 10.6052/j.issn.1000-4750.2023.01.0061
Citation: WU Chen-wei, XUE Jian-yang, SONG De-jun, ZHANG Jia-he. EXPERIMENTAL RESEARCH AND FINITE ELEMENT ANALYSIS ON AXIAL COMPRESSION PERFORMANCE OF INCLINED PINGSHENKE DOU-GONG BRACKETS[J]. Engineering Mechanics. DOI: 10.6052/j.issn.1000-4750.2023.01.0061

歪闪平身科斗栱轴压性能试验研究及有限元分析

EXPERIMENTAL RESEARCH AND FINITE ELEMENT ANALYSIS ON AXIAL COMPRESSION PERFORMANCE OF INCLINED PINGSHENKE DOU-GONG BRACKETS

  • 摘要: 为研究歪闪平身科斗栱的轴压性能,制作了4个不同歪闪角度的足尺平身科斗栱试件,通过向正心桁和挑檐桁的下表面、平板枋顶面塞入木楔来实现斗栱整体歪闪。通过轴压加载试验,得到了斗栱的破坏模式、荷载-位移曲线、承载力和刚度退化以及变形能力、构件荷载-位移关系。采用有限元软件模拟了歪闪斗栱轴压加载,模拟结果与试验结果吻合较好。在此基础上,进行了参数分析,研究了木材横纹抗压强度、横纹弹性模量和构件间摩擦系数对斗栱刚度和变形能力的影响。结果表明:无歪闪和歪闪5.0°斗栱被整体压缩、大斗压溃、正心瓜栱和单翘端部劈裂破坏;歪闪7.5°和10.0°斗栱的构件破坏较轻,破坏模式变为斗栱大幅度转动。随着歪闪角度的增加,斗栱的承载力退化程度增加,变形能力和卸载后弹性变形恢复能力减小。在歪闪斗栱面宽(进深)方向,自上向下构件的压缩刚度依次增加(减小)。增加横纹抗压强度、横纹弹性模量和摩擦系数均可增加塑性阶段刚度,减小极限位移。研究成果可为古建筑木结构歪闪平身科斗栱的受力分析和科学保护提供参考。

     

    Abstract: In order to study the axial compression performance of the inclined Pingshenke Dou-Gong bracket, four full-scale bracket specimens with different inclined angles were fabricated. Wooden wedges were inserted into the lower surfaces of the Zhengxin-Heng, the Tiaoyan-Heng, and the top surface of the Pingban-Fang to realize the overall inclination. Through the axial compressive loading test, the failure patterns, load-displacement curves, the degradation of bearing capacities and stiffness, deformation abilities, and load-displacement relationship of components were obtained. The finite element method was used to simulate the axial compression, and the simulation results agreed with the experimental results. On this basis, parameter analyses were carried out. The effects of compressive strength and elastic moduli in the perpendicular-to-grain direction of wood, and friction coefficients among timber components on the vertical stiffness and deformation abilities of the bracket were studied. The results show that when uninclined brackets and brackets with a 5° inclination angle were compressed as a whole, the Da-Dou was crushed and both ends of the Zhengxingua-Gong and Dan-Qiao were split and damaged. The damage of the components of the brackets with 7.5° and 10° inclination angles was relatively slight, and the failure mode was changed to large rotation. With the increase of the inclination angles, the degradation degree of the bearing capacities of the bracket increased, and the deformation capacity and the recovery ability after unloading decreased. In the direction of width (overhanging) of the inclined bracket, the compressive stiffness of the components increased (decreased) sequentially from top to bottom. Increasing the compressive strength and elastic moduli in the perpendicular-to-grain direction, and friction coefficients could increase the stiffness in the plastic stage and decrease the ultimate displacement. The research results can provide a reference for the mechanical analyses and scientific protection of the inclined Pingshenke Dou-Gong bracket in ancient timber-frame buildings.

     

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