受压容器的横截面通常设计成圆形的。但为了满足特殊的工艺、设备设计和制造方面的要求,也需要设计承受内压的非圆形截面的结构。例如锅炉的联箱、某些蒸汽锅炉,消毒箱、换热器等,就常设计成矩形壳体。矩形容器的强度计算的力学模型可分为两类:刚架模型和平板模型。刚架模型是从矩形 The cross-section of the pressure vessel is usually circular. However, in order to meet special process, equipment design and manufacturing requirements, it is also necessary to design a structure with a non-circular cross section under internal pressure. For example, the boiler header, some steam boilers, sterilization boxes, heat exchangers, etc., often designed as a rectangular shell. The mechanical models for calculating the strength of rectangular vessels can be divided into two categories: rigid frame models and slab models. Rigid frame model is from rectangle