考虑应变率影响的厚壁筒残余应力场分析

THE INFLUENCE OF STRAIN-RATE ON THE RESIDUAL STRESS FIELDS OF THICK-WALLED CYLINDER

  • 摘要: 本文针对弹塑性拉压循环加卸载条件下,不同的应变率(10-4-10-2s-1)变化,对高强钢(PCrNi3MoV)材料的屈服应力、应变硬化参数和反向屈服应力等参量的影响进行了实验研究,提出了便于理论计算的简化弹塑性本构模型,并假设拉屈服应力与压屈服应力的差值不随应变率的不同而发生变化,这一假定与实验结果相符合,且便于工程计算。针对厚壁筒自紧加工工艺的残余应力场分析问题,用本文提出的模型对厚壁筒在四种不同的应变率条件下进行自紧加工时残余应力场的变化及不同的自紧效果进行了详细的分析和比较,并提出了改进工艺过程和提高自紧效果的建设性意见。

     

    Abstract: In this paper, the residual stress fields on the autofrettage technique of thickwalled cylinder are analyzed in detail. The experiments concerning the influence of strain-rate on mechanical parameters of gun barrel are carried out under uniaxial tensile and compressive cyclic loading condition. The effects of four different strain rates on the yield stresses, the hardening parameters and the reverse yield stresses have been compared. On the basis of the experimental results, an elasto-visco-plastic model has been proposed to analyze the residual stress fields of autofretted tube under the assumption that the difference between the tensile and the reverse yield stresses is independent of strain-rate.The effects of strain rates on the mechanical autofretted tube are evaluated by using the proposed rate-dependent constitutive model.Some useful suggestions for improving the autofrettage technique are presented

     

/

返回文章
返回