新旧杆塔技术规定对刚性法兰设计对比研究

Comparison of Rigid Flanges Designed by New and Old Transmission Line Regulation

选取输电塔架中常见的157个法兰节点,分别按照新旧杆塔技术规范中刚性法兰的计算方法进行设计,并对比尺寸,分析了新旧规范对法兰板厚度的影响规律。为研究新规范设计方法的合理性,采用ANSYS对20个法兰进行非线性数值模拟,认为新规范在法兰板设计方面较旧规范更为合理。此外,研究中发现法兰中的螺栓处于拉弯受力状态,因此,以1个节点为例,通过改变有限元参数,分析比较了法兰板厚度、肋板厚度、肋板高度对螺栓受力的影响,指出增大法兰板厚度对螺栓受力性能改善最为明显。结合实际设计中螺栓的设计利用率,建议设计时将法兰板厚度计算公式t=5M/f中的系数5调整为6,可增大10%左右的板厚,改善螺栓受力情况,供实际工程应用参考。

The research picked 157 common joints from transmission towers and design rigid flanges respectively based on the new edition of technical regulation of design for steel tubular tower structures of overhead transmission line and the old one. The comparison showed the influence rules on thickness of flange plates. In order to check the rationality of the design method in the new edition, the research conducted a nonlinear FE analysis on 20 flanges with help of ANSYS. The result shows that the design method in the new edition is relatively more reasonable than that in the old edition. Since the bolts in flanges is under tensile force with bending moment, a FEM parametric analysis was conducted. The result shows that it is better to increase the thickness of the flange plate rather than the thickness or the height of ribs to improve the loading situation of bolts. According to the research and the design utilization of bolts in reality, it is suggested that replacing the factor 5 with 6 in plate thickness formula t = 5M/f when designing flanges.