中文摘要：

为了研究几何参数和材料参数对回弹的影响，基于弹塑性理论推导了最终弯曲半径和回弹角度的近似计算公式，结合有限元模拟，分析几何参数和材料参数对21—6—9高强不锈钢管材数控弯曲回弹规律的影响，并对理论解析、有限元模拟和试验结果进行对比。结果表明：最终弯曲半径随着弯曲半径、强度系数的增大或弹性模量、硬化指数的减小而增大，且与弯曲角度无关；回弹角度随着弯曲角度、相对弯曲半径、强度系数的增大或弹性模量、硬化指数的减小而增大；有限元模拟结果和试验结果吻合良好，能够较精确地预测回弹；理论解析与试验结果对比误差较大，但能够反映回弹角的变化趋势。

英文摘要：

In order to study the effects of geometric parameters and material parameters on springback of bent tube, the formulas of the final bending radius and springback angle were derived using the elastic plastic theory, then combined with theoretical and FE analysis, the effects of geometric parameters and material parameters on springback law of 21-6-9 high strength stainless steel tube during NC bending were analyzed, then the theoretical analysis, FE simulation and experimental results were compared. The results show that the final bending radius increases with the increase of bending radius, strength coefficient, or the decrease of elastic modulus and hardening exponent, and it is independent of bending angle. The springback angle increases with the increase of bending angle, relative bending radius, strength coefficient or the decrease of elastic modulus, hardening exponent. The simulation results and experimental ones agree with each other well, which can predict springback more accurately. Comparing theoretical analysis with experimental results, the error is bigger, but it can reflect the change trend of springback angle.