负载下焊接加固铁塔角钢轴压构件的受力性能

Mechanical Behavior of Angle Steel Axial Compression Members of Steel Tower Reinforced by Welding while Under Load

摘要:

为研究不同加固截面形式、初始负载大小对铁塔轴压角钢焊接加固后受力性能的影响，选择了方形和L形两种加固截面形式，在4档不同初始负载下进行了焊接加固角钢的轴压单调加载静力试验，得到了焊接加固后角钢的荷载位移曲线、极限稳定承载力和破坏模式.针对试验试件建立了有限元模型，进行了考虑焊接间接热力耦合方法的数值模拟计算. 对比试验和数值计算结果表明：两种加固截面破坏模式为整体弯曲失稳；相对于方形加固截面试件，L形加固截面试件对于热输入的影响更加敏感，延性较差；当初始负载名义应力比不超过0.3时，可以忽略初始负载大小对加固后角钢轴压构件极限稳定承载力的影响.

Abstract:

In order to investigate the influences of different forms of reinforced section and initial load on mechanical behaviors of axial compression angle steel in steel tower following weld reinforcing process, two forms of reinforced section, square and Lshape, were selected. Under the four different initial load, the static load test of angle steel reinforced by welding was conducted. The loaddisplacement curve, the ultimate stability bearing capacity as well as the failure mode of reinforced angle steel were obtained. According to the static test, finite element models were established and the numerical simulation was carried out to take into account the indirect thermostructure coupling analysis method. Both the test and analysis results show that the failure mode of two reinforced sections are global bending buckling; Compared to the specimens with square cross section, Lshape specimens are more sensitive to the heat input, but ductility is poorer; If the nominal stress ratio of initial load is less than 0.3, the effect of initial axial compressive load on the ultimate stability bearing capacity of angle steel axial compression members reinforced by welding is negligible.