【作者】 王渊阳；

【导师】 武振宇；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2007， 硕士

【摘要】 为研究直接焊接方钢管桁架的静力工作性能,进行了两榀直接焊接K型间隙方钢管桁架静力试验。通过对桁架的破坏模式、荷载—轴力曲线、支杆轴力—相对位移曲线、荷载—挠度曲线和极限承载力的分析,研究了不同高跨比方钢管桁架的静力工作性能。采用ANSYS程序依据桁架试件的实际尺寸建模,并模拟了试验边界条件和加载方式进行计算。建立了三个有限元壳单元桁架模型。模型1是不考虑焊缝影响的壳单元桁架;模型2是通过局部增大支杆壁厚来考虑焊缝影响的壳单元桁架;模型3是通过在支杆四周设置附加壳单元来考虑焊缝影响的壳单元桁架。同时将荷载—轴力曲线、支杆轴力—相对位移曲线、荷载—挠度曲线和桁架破坏模式的试验结果与有限元计算结果进行了比较,验证了利用ANSYS程序进行钢管桁架静力性能研究的可行性。此外,通过对有限元计算结果的分析,掌握了钢管桁架中K型间隙节点的应力分布和塑性发展过程。采用ANSYS程序中的壳单元来模拟管桁架虽然准确性较高,但是模型的建立和计算比较费时间。本文用杆单元和梁单元建立的简化模型计算了桁架的杆件轴力和挠度。与有限元壳单元模型计算结果比较表明,简化模型不仅准确,而且模型建立和计算所用的时间较少。本课题的试验研究和有限元分析将为方钢管桁架在我国发展提供一定的试验数据和分析方法。更多还原

【Abstract】 A static test program on two trusses which include directly welded gap K-joints is carried out, the aim of the work is to study the static behavior of the directly welded SHS truss. Failure modes、load-axial force curves,、branch axial force-relative displacement curves、load-deflection curves and ultimate capacity of trusses are analyzed. The static behavior of SHS truss with different height-span ratio is studied.The FE Package program ANSYS is adopted to calculate static strength of the SHS trusses. The truss size、boundary condition and loading mode are simulated by the FE models. Three FE models with shell elements are developed. The first model with shell elements doesn’t consider welds. The second model with shell elements considers welds by increasing the thickness of branch wall. The third model with shell elements considers welds by adding some shell elements around the branch. At the same time, load-axial force curves、branch axial force-relative displacement curves、load-deflection curves and failure modes of trusses acquired from the experiment are compared with that from the calculations. It is proved that ANSYS is feasible to calculate the static strength of SHS truss. Furthermore, the distributions of stress and developing process of the plastic zone are acquired by the finite element analysis.It is very accurate for ANSYS to simulate SHS truss with shell elements. However, it will take a lot of time to develop the model and calculate it. The simple model is developed using link1 and beam3 elements. The axial force and deflection of truss acquired from the simple model are compared with that from the FE model with shell elements. Not only the results acquired from the simple model are very accurate, but also it takes less time to develop the model and calculate it.The experimental research and FE analysis on SHS truss in this thesis will provide the experimental data and analytical method of SHS truss for the further development of SHS truss in China.更多还原