双层组合厚壁圆筒弹脆塑性极限内压统一解

ELASTIC-BRITTLE-PLASTIC UNIFIED SOLUTIONS OF LIMIT INTERNAL PRESSURE FOR DOUBLE-LAYERED COMBINED THICK-WALLED CYLINDER

基于三剪统一强度准则和弹脆塑性软化模型,考虑材料的脆性软化和中间主应力效应,推导了双层组合厚壁圆筒弹脆塑性极限内压统一解,探讨了粘聚力、内摩擦角、半径比、强度理论参数和中间主应力系数的影响特性,克服了以往基于Tresca屈服准则、Mises屈服准则或双剪强度理论的理想弹塑性解的不足。研究结果表明:中间主应力、材料模型和脆性软化对厚壁圆筒的极限内压均有显著影响。该文所得统一解具有广泛的适用性和理论意义,不但可退化为现有公式,而且还能得到系列化的新解答,对组合厚壁圆筒的设计及工程应用有重要参考价值。

With the consideration of brittle softening and intermediate principal stress, the elastic-brittle-plastic unified solutions of limit internal pressure for double-layered combined thick-walled cylinder are presented based on both the triple-shear unified strength criterion and the elastic-brittle-plastic softening model. The effects of the cohesion, internal friction angle, radius ratio, strength theory parameter and the intermediate principal stress coefficient on the unified solutions are discussed. The new unified solutions overcome the shortages of the existing elastic-perfectly plastic solutions based on the Tresca yield criterion, Mises yield criterion or twin shear strength theory. It is shown that the influence of intermediate principal stress, material model and brittle softening on the limit internal pressure is significant. The unified solutions obtained in this paper have a wide applicability and theoretical significance, which can be naturally degraded to the existing formula and can get a series of new solutions. Therefore, the unified solutions have an important practical value for the optimum design and engineering application of combined thick-walled cylinder.