套管滚压整形力学分析及单次整形极限研究

滚珠整形器在变形套管修复中应用越来越广泛,而整形时常凭经验确定整形量,若单次整形量过大极易造成套管损坏。为此,给出套管单次整形极限研究方法,采用多线性等向强化模型,考虑套管的材料和接触双重非线性特性,建立了滚压整形缩径变形套管有限元模型,给出了求解策略,并采用试验研究的方法验证了数值模型的合理性。揭示了不同整形量对套管塑性位移及应力分布的影响规律,研究了不同轴向变形长度套管单次整形极限。结果表明:随着套管整形量的增大,套管最大等效应力、塑性位移和残余应力均增大;随着套管轴向变形长度的增大,单次整形极限有减小的趋势,单次整形量最大值不能超过3.6 mm。研究结果可为滚压整形变形套管现场施工提供理论指导。

Mechanical Analysis and Single Shaping Limit Research of Casing Rolling Shaping

The ball shaper is more and more widely used in the repair of the deformed casing.However,the shaping dimension is often determined by experience during shaping.If the dimension of single shaping is too large,the casing is easily damaged.To this end,firstly,the method of single shaping limit research of casing is given.Secondly,the multi-linear isotropic strengthening model is adopted.Considering the material and contact double nonlinear characteristics of casing,a finite element model(FEM)of rolling shaping reducing deformation casing was established.The solution strategy was given and the rationality of the numerical model was verified by experimental research.Finally,the influence of different shaping dimension on the plastic displacement and stress distribution of the casing was revealed.The single shaping limit of the casing with different axial deformation lengths was researched.The results show that with the increase of the shaping dimension,the maximum equivalent stress of the casing,the plastic displacement and residual stress of the casing are all larger after shaping.As the axial deformation length increases,the single shaping limit has a tendency to decrease.The maximum shaping deformation of the deformed casing cannot exceed 3.6 mm.The research results can provide theoretical guidance for the onsite construction of rolling shaping deformation casing.