航空薄壁弧形结构件喷丸强化变形预测

喷丸强化是一种有效提高工件抗疲劳性能的表面处理工艺，经喷丸强化处理后的航空薄壁弧形结构件发生变形是航空制造领域的共性难题．本文基于变截面曲梁平面弯曲理论，建立了弧形件喷丸诱导应力与变形方程，将得到的构件最大变形与有限元方法计算结果进行对比，所建立理论模型能有效预测弧形件喷丸强化后的变形．讨论了喷丸压力和喷丸区域对喷丸变形的影响，结果表明：喷丸强化工艺仅作用于弧形件腹板表面时，弧形件变形以径向收缩为主；喷丸强化工艺仅作用于弧形件筋板表面时，弧形件变形以径向扩张为主；与局部喷丸相比，对弧形件所有表面喷丸强化时，弧形件弯曲变形减小，轴向伸长增大．

Prediction on Distortion in Shot Peening of Thin-Wall Arc-Shaped Frame

Shot peening is a surface strengthening method to significantly improve fatigue resistance of the peened part, which is widely used in surface treatment of thin-walled arc-shaped frame. The distortion of aeronautical component introduced by shot peening process is a serious issue in aviation industry. According to the theory of elastic mechanics, the mechanical model of stress and deformation of arc shaped frame is introduced. Based on the model, the equations of residual stress and deformation are established, and the calculation of maximum deflection of the component is completed. The finite element model is adopted to validate the theoretical method. Results show that the theoretical method can predict the deformation of arc shaped frame after shot peening process under the specified initial stress and structure parameters. The characteristics of deformation of different shot peening process for arc-shaped frame are studied. It is found that the arc-shaped frame under shot peening process on the web will shrink in the radial directions; the arc-shaped frame under shot peening process on the rib will extend in the radial directions; compared with the shot peening process applied to local surface, the shot peening process applied to all surfaces induce higher axial deformation and smaller radial deformation.