梯形截面箱梁扭心位置计算

Calculation of Torsion Center Postion of the Trapezoldal Section for Box Beam

箱形截面是大跨度桥梁优先采用的截面型式 ,截面扭转中心位置的计算是薄壁箱梁结构内力分析的重要组成部分 .根据箱形薄壁梁约束扭转计算的乌曼斯第二理论 ,对桥梁工程中常用的梯形截面薄壁箱形梁的截面特性及扭转中心位置计算公式进行了理论推导 ,得出了具有显式表达式的梯形截面薄壁箱梁扭心位置计算公式 .数值算例表明 ,该计算公式正确、使用方便 ,且可适用于矩形截面箱梁特例情况 ,计算公式具有适用性 。

Box sections are preferential forms used in long span-bridges, and the calculation of the positions of their torsion centers is an important part for analyzing the internal force of thin walled box beams. According to the theory of constrained torsion, which is on calculating the constrained torsion of thin walled box beams, the characteristics of the trapezoidal sections are theoretically derived, and the formula for calculating the positions of their torsion centers is presented in this paper. Compared with numerical examples, the formula proves to be accurate, and can be used easily. Moreover, in the case of rectangle sections of box beams which are special forms of the trapezoidal sections,the formula is also effective, and it can be applied to practical projects.