摘要:
杭州西站站房钢屋盖是一种网架-桁架结合的复杂空间结构体系,因此在该结构中存在大量多杆交汇的连接问题,对这类复杂连接部分通常采用铸钢件的形式予以解决。由于此类节点交汇杆件多、受力复杂,造成分析难度大。通过有限元与试验研究的方法对杭州西站钢屋盖中的复杂铸钢节点进行分析,以此判别该铸钢节点设计的安全性与可靠性。采用有限元分析方法时,对节点在设计荷载与极限荷载两种工况下分别进行计算,设计荷载取为节点的最不利荷载工况,极限荷载为设计荷载的3倍。通过有限元分析发现:在设计荷载下节点应力水平均低于材料的屈服强度,最大应力为179.088 MPa,等效塑性应变为0;在极限荷载作用下,节点部分区域应力超过材料屈服强度,但整体荷载-位移曲线仍为线性。此后,对该铸钢节点进行材性试验及足尺试验研究。在足尺试验中,试验最大荷载为设计荷载的1.3倍,加载时,由0至最大加载力均分为26级,试验从开始至结束均未观察到试件出现明显的变形,试验过程中各应变片所采集的数据显示铸钢节点最大应变为1 036×10-6。将试验结果与有限元计算结果对比,吻合程度良好,表明:有限元计算结果较可靠;铸钢节点在设计荷载下处于完全弹性状态,在极限荷载作用下,尽管铸钢节点出现部分塑性,但未对节点整体力学性能产生影响,由此可判断所研究的节点是安全、可靠的,为未来相关工程的铸钢节点设计提供参考。
Abstract:
The steel roof of Hangzhou West Railway Station is a complex spatial structure system which is the combination of grid and truss. Thus, there are many multi-pole intersection connection problems in this structure, which could be solved by the cast steel joints. Due to the large number of intersecting members and complex forces of the such joint, the analysis is difficult. In this paper, the complex cast steel joint in the steel roof of Hangzhou West Railway Station was analyzed by finite element and tested to determine the safety and reliability of the design of the cast steel joint.When the finite element analysis method was adopted, the joint was discussed under the design load and the limit load respectively, and the design load was taken as the most unfavorable load case of the joint, and the limit load was 3 times the design load. The finite element analysis results indicated that under the design load, the stress level of the joint was lower than the yield strength of the material. The maximum stress was 179.088 MPa, and the equivalent plastic strain was 0. Under the limit load, the stress in some parts of the joint exceeded the yield strength of the material, but the overall load-displacement curves were still linear. Since then, experimental studies had been carried out on the cast steel joint. A full-scale test study was carried out on this joint, and the maximum test load is 1.3 times the design load. When loading, the load force was divided into 26 levels from 0 to maximum. From the beginning to the end of the test, no obvious deformation of the cast steel joint was observed. Moreover, the data collected by each strain gauge showed that the maximum strain of the cast steel joint was 1 036×10-6. This paper compared the test results with the finite element calculation results, and the degree of agreement was good, which showed the accuracy of the finite element calculation results. And the joint was in a fully elastic state under the design load, and the partial plasticity did not affect the overall mechanical performance of the joint. Therefore, it could be judged that the joint is safe and reliable, which could provide a reference for the design of cast steel joint in related projects in the future.