胶合木—混凝土组合梁力学性能研究

发布时间：2018-11-28 13:27

【摘要】：随着经济的发展和社会的进步,人们越来越关注建筑的生态和可持续发展。木材作为一种绿色环保的天然资源,再次得到重视。现代木-混凝土组合结构由木结构和混凝土结构发展而来,木材顺纹受拉性能良好,混凝土受压性能良好,木-混凝土组合结构能充分发挥两种材料各自的优势,克服木结构和混凝土结构自身的诸多不足,已成为一种极具潜力的新型组合结构。在荷载作用下,保证两种材料共同受力和变形协调是充分发挥其承载能力的关键。然而,现代木-混凝土组合结构桥梁的研究和应用尚处于起步阶段,设计理论和设计方法亟待完善。为此,本文结合已有相关研究工作,对木-混凝土组合梁进行受力性能研究,主要结论如下:(1)对木-混凝土组合梁进行静力试验,测试典型截面的应变、挠度、滑移等相关参数,得到截面应变分布规律以及滑移、挠度随荷载变化的规律等。(2)针对混凝土剪切破坏和钉杆弯曲变形造成连接失效的破坏机理,建立木-混组合梁槽口钉类抗剪承载力的计算公式,并将计算结果与试验结果进行比较,吻合良好,能够较好地反映钉杆弯曲破坏时槽口钉类连接件抗剪承载力。(3)基于折减刚度法的研究思路,对木-混凝土组合梁提出了修正折减刚度法,并利用试验结果进行验证,同时与换算截面法以及γ法进行对比。计算结果表明,修正折减刚度法适用于木-混凝土组合梁弹性阶段的挠度计算。(4)利用ANSYS有限元软件对木-混凝土组合梁进行数值模拟计算,并与试验结果进行对比。结果表明,ANSYS有限元数值模拟的荷载-挠度曲线在加载前期与试验结果比较吻合。(5)运用不同的理论方法计算试验梁竖向弯曲模态的前3阶频率,再利用Midas有限元软件进行竖向弯曲模态分析,得到试验梁竖向弯曲模态的前3阶振型和相应频率。计算结果表明,γ法与修正折减刚度法因考虑滑移效应,其竖向弯曲模态理论基频与数值模拟总体上比较接近。
[Abstract]:With the development of economy and society, people pay more and more attention to the ecology and sustainable development of architecture. Wood, as a natural resource of green and environmental protection, is paid more attention to again. The modern wood-concrete composite structure is developed from wood structure and concrete structure. The tensile property of wood is good, the compressive performance of concrete is good, and the wood-concrete composite structure can give full play to the advantages of the two kinds of materials. To overcome the shortcomings of wood structure and concrete structure itself, it has become a new type of composite structure with great potential. Under the action of load, the key to give full play to the bearing capacity of the two materials is to ensure the coordination of their common forces and deformation. However, the research and application of modern wood-concrete composite structure bridge is still in its infancy, and the design theory and design method need to be improved. The main conclusions are as follows: (1) static test of wood-concrete composite beam is carried out to test the strain and deflection of typical section. The relative parameters such as slip, strain distribution of cross section and the variation of slip and deflection with load are obtained. (2) the failure mechanism of joint failure caused by shear failure of concrete and bending deformation of nail rod is discussed. A formula for calculating the shear capacity of wood concrete composite beams is established. The calculated results are in good agreement with the experimental results. It can better reflect the shear bearing capacity of slot nail connectors when the nail rod is bending failure. (3) based on the research ideas of the reduced stiffness method, the modified reduced stiffness method is proposed for wood concrete composite beams, and the experimental results are used to verify it. At the same time, it is compared with the conversion section method and 纬 method. The results show that the modified stiffness reduction method is suitable for the deflection calculation of wood-concrete composite beams in elastic stage. (4) the numerical simulation of wood-concrete composite beams is carried out by using ANSYS finite element software, and the results are compared with the experimental results. The results show that the load-deflection curves simulated by the ANSYS finite element method are in good agreement with the experimental results in the early stage of loading. (5) the first three order frequencies of the vertical bending modes of the test beams are calculated by different theoretical methods. The first three modes and corresponding frequencies of the vertical bending mode of the test beam are obtained by using the Midas finite element software. The calculation results show that the fundamental frequency of the vertical bending mode theory is close to that of the numerical simulation because of the slip effect in the 纬 method and the modified reduction stiffness method.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

【相似文献】