钢变电构架考虑损伤的承载能力计算模型研究

Computation Model Study of Load-Bearing Capacity of Steel Structural Gantry of Switchyard Considering Damage

针对无侧向支撑的两跨人字形钢结构变电构架,在构架柱损伤前后,分别进行了考虑结构二阶效应的承载能力分析。为了模拟构架柱的凹陷损伤,分别采用了等效刚度模拟方法和区段损伤模拟方法。分析中考虑了构架柱的初始几何缺陷,加载过程分别考虑了几何非线性、材料非线性以及两种非线性因素共同作用的影响。在导线荷载作用下,通过分析对比变电构架受损前后的二阶弹性、一阶弹塑性和二阶弹塑性曲线,得到了其承载能力的变化规律:变电构架的极限承载能力主要受弹塑性二阶效应的影响,但与弹性极限差别较大;与区段损伤模拟方法相比,采用等效刚度模拟方法时,其极限承载能力降低较为明显。

The load-bearing capacity of two-span character shaped steel structural gantry of switchyard with no lateral supports before and after the damage of gantry column was analysed considering second-order effect of the structure. Equivalent stiffness simulation method and part damage simulation method were used separately so as to simulate the dent damage of gantry column. Initial geometrical imperfection of gantry column was considered in the analysis, and geometrical nonlinearity, material nonlinearity and the two were considered separately in the loading process. To wire loads, the variation laws of load-bearing capacity have been found through analysis and comparison of second-order elastic curve, first-order elastic-plastic curve and second-order elastic-plastic curve, which were obtained from gantry of switchyard before and after being damaged. The conclusions are as follows： the ultimate load-bearing capacity of gantry of switchyard is mainly influenced by elastic-plastic second-order effect, but it is much different from elastic ultimate load-bearing capacity; the ultimate load-bearing capacity is reduced more evidently when equivalent stiffness simulation method is used compared with part damage simulation method.