H型钢简支梁受扭正应力计算方法探讨

Discussion on the calculation method of the torsion normal stress in simply supported H-shaped steel beams

为使H型钢简支梁受扭正应力计算方便,通过对理论计算公式的分析,提出了抗扭特别截面模量Wt'的概念,并且在计算中引入H型钢简支梁截面模量Wx和抗扭特别截面模量Wt'的比值n1来简化公式。针对我国热轧H型钢简支梁的特点,以及常用跨高比下n1值的分析,提出了n1在各种情况下的估算公式和适用范围。通过验证说明n1值的估算公式是可以满足H型钢简支梁受扭正应力值的估算需要。最后通过对我国常用热轧H型钢简支梁的n1值计算,说明其数值大小是在一定范围之内,设计人员可根据此值,对H型钢简支梁受扭正应力计算有更直观的认识。

In order to make the torsion normal stress of simply supported H-shaped steel beams be calculated conveniently,through analyzing the formula of theoretical calculation,the concept of torsional special section modulus Wt＇ was proposed,and the ratio n1 of section modulus Wxand torsional special section modulus Wt＇ was introduced for simplifying the formula.According to the characteristics of simply supported H-shaped steel beams and the analysis of n1 values in the span-depth ratio of common use,the estimation formula and application range of n1 were presented. It is proved that the estimation formula of n1 value is able to meet the need of the torsion normal stress of simply supported H-shaped steel beams. Finally through to the common hot-rolled simply supported H-shaped steel beams n1 values,indicating that the value is within a certain range,the designer can be on the basis of the value,a more intuitive understanding wound be take shape about the calculation of the torsion normal stress of simply supported H-shaped steel beams.