摘要:
胶合木-混凝土简支组合梁结合了胶合木与混凝土两种材料的结构力学特性,木梁通过剪力连接件与混凝土板形成一个整体,以此达到共同工作的作用。目前,在多高层建筑以及木结构建筑中得到了广泛的应用。另外,木结构符合绿色建筑的发展理念,发展木结构建筑可以降低建筑行业对环境的影响,具有十分重要的意义。为研究荷载形式和栓钉布置方式对胶合木-混凝土简支组合梁的滑移、挠度以及内力的影响,主要利用ANSYS软件进行建模分析,并与均匀情况布置下的栓钉进行对比分析,从而验证模型的正确性。基本假设为胶合木与混凝土为理想的线弹性材料,不考虑混凝土的开裂,基于此,讨论荷载形式、栓钉布置方式对滑移、挠度和内力的影响。建模思路:对于混凝土C30采用Solid 65单元进行建模,木梁则采用Solid 45单元,而栓钉则采用Conbine 39,栓钉本构采用Lukaszewska E中所拟合出的SST+S型号的连接件。同时进行参数化分析,输出组合梁的滑移、挠度和内力,并与胶合木-混凝土简支组合梁理论值做对比分析。结果表明:虽然木材是一种正交各向异性的材料,但是可以按材料力学的相关理论取与受力方向一致的弹性模量,通过钢-混组合梁的理论公式来推导胶合木-混凝土组合梁的公式,并且其滑移分布规律与钢-混组合梁分布规律一致,呈现出梁端大、中间小的分布规律,其有效刚度可以采用欧洲规范EN 1995-1-1中的“γ”进行计算,误差非常小;可以通过钢-混组合梁滑移理论的思路来推导胶合木-混凝土组合梁滑移理论公式,误差在7%左右;在剪力图面积大小相等时,对称集中荷载下组合梁的滑移及挠度最大,在工程中应尽量避免;在大多数荷载作用下,应根据滑移图合理分段布置栓钉,可以有效减少组合梁的滑移和挠度;ANSYS有限元软件可以正确模拟胶合木-混凝土简支组合梁,且具有很高的精度,为考虑正交各向异性的材料提供了方法和思路。
Abstract:
The Glued-laminated timber-concrete simply-supported composite beam combines the structural mechanical properties of both glued wood and concrete. The wood beam forms a whole with the concrete slab through shear connectors, thus achieving a common working effect, and is widely used in multi-story buildings as well as in wood-frame buildings. Secondly, wood structure is in line with the development concept of green building, and the development of wood structure building can reduce the impact of the construction industry on the environment, which is of great importance.To investigate the effects of load form and peg arrangement on the slip, deflection and internal forces of Glued-laminated timber-concrete simply-supported composite beam, the modeling analysis was mainly performed using Ansys software and compared with the pegs in a uniform case arrangement to verify the correctness of the model. The basic assumption is that glulam and concrete are ideal linear elastic materials and that cracking of concrete is not considered. Based on this, this paper discusses the effects of the form of loading and the way the pegs are arranged on slip, deflection and internal forces. The modeling methods are as follow: for concrete C30, solid 65 units were used for modeling, wood was modeled with solid 45 units, while pegs were modeled and analyzed with conbine 39, and the constitutive model of pegs was modeled with the SST+S type joint fitted in Lukaszewska E. And parametric analysis is performed, and the slip, deflection and internal force of the combined beam were output. And compare the analysis with the theoretical values of the glued laminated wood-concrete composite beam.The results show that although wood is an orthotropic anisotropic material, it is possible to derive the equation for the Glued-laminated timber-concrete simply-supported composite beam by taking the modulus of elasticity in the same direction as the force according to the knowledge of mechanics of materials, and by using the theoretical equation for steel-composite combination beams. And its slip distribution law is consistent with the distribution law of steel-concrete combination beam, showing the distribution law of large at the end of the beam and small in the middle. Its effective stiffness can be calculated by using the "γ" in Eurocode EN 1995-1-1, and the error is very small. In conclusion, it is possible to derive the equation of glulam-concrete composite beam slip theory by the idea of steel-concrete composite beam slip theory, and the error is about 7%. Under the condition that the area of shear diagram is equal in size, the slip and deflection of the composite beam under symmetrical concentrated load are the largest, which should be avoided as much as possible in the project. Under most conditions, the pins should be arranged in reasonable segments according to the slip diagram, which can effectively reduce the slip and deflection of the composite beam. The Ansys finite element software can correctly simulate the Glued-laminated timber-concrete simply-supported composite beam with high accuracy, which provides methods and ideas for considering materials with orthotropic anisotropy.
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