一、前言对于重型汽车式起重机车架设计,往往由于起重机在侧向起重时有很大的不平衡扭矩,车架需要有很大的抗扭刚度,因此车架采用多箱闭口截面是经济合理的。这种多箱截面,由于构造原因其特点是截面中主要部份是闭口多箱截面,而另一小部份又往往是开口截面(如图1所示)。本文运用已有的开口截面和闭口截面薄壁杆件计算理论,对如图1型式的截面进行应力分析。二、薄壁截面计算公式的导演 I. Introduction For heavy duty truck crane frame design, often due to the crane in the lateral lifting has a lot of unbalanced torque, the frame needs a lot of torsional stiffness, so the frame with multi-box closed section is economical reasonable. This multi-box section, due to its structural features, is characterized by the fact that the major part of the section is the closed multi-box section and the other small section is often the open section (as shown in Figure 1). In this paper, the existing open section and closed section thin-walled rod calculation theory, the section of Figure 1 type stress analysis. Second, the thin section of the formula director