型钢混凝土转换桁架节点施工监控及非线性有限元分析

1、型钢混凝土转换桁架节点施工监控及非线性有限元分析        【中文摘要】型钢混凝土结构是指由型钢和其外包钢筋混凝土共同承受荷载的结构。构件截面中型钢的配置,使结构具有构件截面小、承载力大、抗震性能好、方便施工的优点;截面中钢筋混凝土的配置,克服了型钢防腐、防锈、防火性能差,易发生局部和整体失稳的缺点,抗侧移刚度大,节约钢材,降低了造价1,2。以贵州省委办公业务大楼为工程背景,本工程为下部群楼、上部主体连体、中庭镂空的复杂高层建筑结构。该桁架转换层跨度较大且上部有13楼层的竖向荷载直接作用于桁架之上,桁架节点部位

2、构造复杂且为荷载传递的关键,是保证结构承载力和刚度的重要部位3,4。采用振弦式应变传感器对该工程的型钢桁架节点进行了施工监控;并利用有限元分析软件ANSYS对该工程的桁架节点进行了实体有限元分析,最后对比分析了施工监控与有限元分析的结果,主要内容和结论如下:(1)运用有限元分析软件ANSYS对该办公大楼型钢混凝土转换层桁架节点进行了三维实体弹性和非线性有限元分析,得出了桁架节点的应力应变分布,分析结果为该桁架节点的设计提供了理论参考依据。(2)根据上述有限元分析计算结果确定了该桁架节点的施工监控方案,完成传感器的安装和调试,在各个施工阶段对桁架节点进行了施工监控,得出了各个施工阶段桁架节点的监

3、控数据和节点的实测受力结果。(3)对比分析了节点施工监控中相应测试点的测试结果和计算分析结果,表明弹性有限元分析型钢应变结果与实测应变结果随荷载的增长规律基本一致,但弹性分析应变结果在桁架上部结构完成后都小于实测应变结果;非线性分析型钢应变增长规律与弹性分析基本一致,各个阶段应变值均大于弹性分析结果;印证了考虑非线性后混凝土材料受力性能的差异所导致的混凝土的卸载效应,即混凝土应力减小而对应型钢应力增大应力重分布规律。(4)通过对比分析了影响节点性能的几个参数的不同结果,表明节点混凝土强度的进步对改善内部型钢的受力性能效果有限;节点内部型钢钢板厚度对改善型钢的受力有明显的影响。(5)文中所采用的

4、非线性分析方法对解决此类空间复杂节点在空间复杂荷载条件下的受力分析题目提供了手段,且其分析结果较弹性分析结果偏安全;非线性分析所得到的节点内部的应力应变分布可以更好的指导此类构件设计。');【Abstract】 Steel reinforced concrete structure is the steel structure and outsourcing by the reinforced concrete structure to bear load together. Steel components in the configuration section, so that

5、the structure has a cross-section of small components, large capacity, good seismic performance, the advantages of easy construction; cross-section of reinforced concrete in the configuration of the steel to overcome the anti-corrosion, rust-proof, poor fire performance, prone to partial and the ove

6、rall instability of the shortcomings of anti-lateral stiffness, and to save steel, reducing the cost1,2In this *, taking the Guizhou provincial party committee office building as the engineering business background, the project is made up of the lower part of group for the floor and the upper part o

7、f the main piece, with the complexity of the atrium cut of high-rise building structureThere are 13 floors effect of vertical load direct in the large-span steel reinforced concrete transition truss. The structure of truss node positions is complicated hub of load transfer that is the key parts of t

8、he structure to ensure the bearing capacity and stiffness of the structure3,4.Use vibration wire strain sensor to monitor actual stress status of steel reinforced concrete transfer truss nodes in the process of construction, and use finite element analysis software ANSYS to make entity nonlinear fin

9、ite element analysis of truss nodes of the project. Finally, analyze and contrast the results of construction monitoring and finite element analysis. The main contents and conclusions are as follows:(1) Apply finite element analysis software ANSYS to make three dimensional entity elastic and nonline

10、ar finite element analysis of the steel reinforced concrete transfer truss nodes of the office building, obtained stress and strain distribution of the truss nodes. The analysis results provide theory reference for the design of the truss nodes.(2) Determined scheme of construction monitoring of the

11、 truss nodes according to the above results of finite element analysis, completed installation and debugging of the sensor, made construction monitoring of the truss nodes in each construction stage, obtained monitoring data and analysis results of the truss nodes in each construction stage.(3) Anal

12、yzed and contrasted the results of test points of construction monitoring and finite element analysis. The results showed that the increasing law of the steel strain results of elastic finite element analysis according to the loads is similar to the results of measured strain. But, the results of el

13、astic finite element analysis are all less than the results of measured strain after the upper structure were completed. The increasing law of the steel strain of nonlinear finite element analysis is similar to the results of elastic finite element analysis, and the strain results of each stage are

14、all more than the results of elastic finite element analysis. This corroborated the unloading effect of the concrete cased by the difference of the mechanical behavior of concrete when considered the nonlinearity. That is the law of stress redistribution of the concrete stress decreased and the corr

15、esponding steel stress increased(4) Through analyzing and contrasting the different results of several parameters witch affect the performance of the nodes, show that the effect of the increasing of the concrete strength improving the mechanical behavior of the internal steel is limited. The effect of the internal steel plate thickness of the node improving the mechanical behavior of the steel is significant.(5) Nonlinear finite element analysis method provides means for solving problem of force analysis of this kind spatial complex node at spatial