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完成了10 m/s、15 m/s和20 m/s来流风速下的2个角钢输电铁塔横担模型风洞试验,得到了19个风向角下横担的风轴阻力系数,分析了横担角度风系数、横线向和顺线向风荷载分配系数,构造了角度风系数函数并通过非线性拟合分析确定了拟合参数。在假定阻力系数相同的前提下,分别计算了由风洞试验和规范确定的横担有效投影面积。将试验确定的横担角度风荷载计算参数与国内外规范值进行了对比分析,提出了横担阻力系数、角度风系数和荷载分配系数的取值建议。中国规范计算横担阻力系数时,其计算式中的角钢构件阻力系数(1.3)建议由单片桁架阻力系数代替;风向角为0°时的横线向风荷载和风向角为30°时的顺线向风荷载取值偏于保守。
The wind tunnel test of two angle steel crossbeam crosshead models with 10 m / s, 15 m / s and 20 m / s incoming wind speed was completed, and the wind resistance coefficient of the crossbeam at 19 wind angles was obtained. Cross arm angle wind coefficient, lateral and forward wind load distribution coefficient, the angle wind coefficient function is constructed and the fitting parameters are determined by nonlinear fitting analysis. Under the assumption of the same drag coefficient, the effective projection area of cross-beam determined by wind tunnel test and specification was calculated respectively. The comparatively analysis of the calculated wind load parameters at the cross arm angles and the normative values at home and abroad was made. The proposed values of cross arm resistance coefficient, angle wind coefficient and load distribution coefficient were proposed. In China, when calculating the cross-sectional resistance coefficient, the resistance coefficient (1.3) of the angle member in the calculation formula is suggested to be replaced by the resistance coefficient of the monolithic truss. When the horizontal line wind direction is 0 ° and the wind load and the wind direction angle are 30 ° Downwind wind load values tend to be conservative.