一、概述开口薄壁杆件约束扭转的实用理論是符拉索夫在1936年建立的,目前这个理論已广泛地应用于航空、造船、建筑等各种工程实际领域,在车辆强度计算中同样得到了很多应用. 在符拉索夫理論中,杆件横截面上各点的纵向位移都以截面中线各点之纵向位移作为标准,亦即假定横截面上的约束扭转正应力沿壁厚是均勻分布的.实际上,杆件约束扭转时,横截面的各别部分不仅会在弧线(切线)方向弯曲,而且沿厚度(法线)方向 I. Introduction The practical theory of open thin-walled rods constraining torsion was established in 1936 by Vlasov. This theory has been widely used in practical fields such as aviation, shipbuilding, and construction. Has been a lot of applications. In Vlasov theory, the longitudinal displacement of each point on the cross-section of the rod is taken as the standard of the longitudinal displacement of each point of the midline of the section, that is, the presumptive stress on the cross-section is the normal stress along the wall thickness. Evenly distributed. In fact, when the rod is restrained from twisting, the individual sections of the cross section will not only bend in the arc (tangent) direction, but also in the direction of the thickness (normal).