开式压力机（包括开式机械压力机及单臂液压机）机身在支柱与上、下梁过渡区处发生破坏现象在国内外时有发生，原因是在该区存在严重应力集中。但目前传统计算方法￣［１］无法反映过渡区的应力集中。本文对该区的应力集中问题进行了深入研究，给出了计算公式。理论计算与实测结果有较好的吻合，为开式压力机机身设计提供了理论依据。 Open presses (including open mechanical presses and single-arm hydraulic press) The failure of the fuselage at the transition zone between the struts and the upper and lower beams occurs both at home and abroad due to the serious stress concentration in the area. However, the traditional calculation method [1] can not reflect the stress concentration in the transition area. This article has carried on the thorough research to the stress concentration problem in this area, has given the calculation formula. The theoretical calculation and the measured results are in good agreement, which provides a theoretical basis for the design of the open press body.