考虑到拉、压异性和中间主应力的影响,运用双剪统一强度理论,对受工作内压作用时预应力组合模具的分层半径、过盈量和弹性极限内压进行了详细的分析研究,得到了预应力圈和凹模取同一强度理论情况下的组合凹模分层半径、过盈量和极限内压的表达式。分析结果表明,分层半径、过盈量不仅跟组合凹模内外径相关,也与组合凹模材料的许用应力、拉压比和中间应力系数等相关。 Taking into account the influence of tension, pressure-difference and intermediate principal stress, the double-shear unified strength theory is used to analyze the stratified radius, interference and elastic internal pressure under the action of internal pressure The expressions of the delamination radius, the interference margin and the limit internal pressure of the composite die under the same strength theory are obtained. The analysis results show that the delamination radius and interference are not only related to the inner and outer diameters of the composite die, but also to the allowable stress, tensile ratio and intermediate stress coefficient of the composite die.