大悬挑变截面梁折线形斜柱钢刚架受力性能试验研究

大悬挑变截面梁折线形斜柱钢刚架，结构型式不规则、受力复杂。为考察其受力性能,评价其安全性，对该结构进行了设计验证和极限承载力的缩尺模型试验研究和有限元分析。试验研究表明：变截面梁折线形斜柱钢刚架在设计荷载作用下均处于弹性状态，在极限承载力试验中，变截面梁与折线形斜柱连接部位最先屈服，2.56倍设计荷载时结构达到极限状态。结合试验结果与有限元计算结果，分析了结构的受力变形特征和内力分布规律，分析表明，有限元计算结果与试验结果吻合良好，试验结果验证了理论分析与原型结构设计的正确性；研究表明，折线形斜柱大悬挑钢刚架结构在保证顶部水平约束的情况下，具有较高的承载能力和足够的安全性。

Experimental research on load-carrying behavior of big cantilever steel frame with variable cross-section beam and zigzag column

The structure of a big cantilever steel frame with variable cross-section beam and zigzag column is irregular and its force distribution is quite complex.  In order to investigate the mechanical performance and the safety of the structure, a scaled model test and FEM analysis were carried out to validate the design validation and the ultimate bearing capacity.  Experimental study shows that the test specimen under the design loads is in elastic state. In the ultimate bearing capacity test, the cantilever beam yield firstly near the connection with the zigzag inclined column. When the load reaches 2.56 times of the design load, the structure reaches the ultimate bearing capacity. According to the results of the test and the FEM analysis, the force distribution and deformation characteristics of the structure were analyzed. The analysis shows that the experimental results match well with the finite-element analysis results. The test results demonstrate the correctness and reliability of the theoretical analysis and the original model of structural design. The study reveals that if provided enough horizontal constraint to the top of the structure, the big cantilever steel frame has high load bearing capacity and can be safe enough.