Study On Correction Theory And Method For Distorted Aeronautical Monolithic Component Due To NC Machining

Distortion correcting is a key process in semi and finished product manufacturing. It is also necessary in aeronautical monolithic component fabricating. At present, distortion correcting of aeronautical monolithic component basically remains at a lower level, which mainly depends on workers' experiences. Because of the complication of distortion and improper correcting operation, fail to meet the requirement of correction often occurs in the workshop of prototype airplane manufacturing. That ineluctably leads to the distorted components discarded as useless. This state of affairs reduces the productivity and lowers the precision of the finished products. Furthermore, production schedule and manufacturing costs of aeronautical product are influenced. In this dissertation, by coalescing theory analysis, finite element calculation and experiment, theory and method for correcting distorted aeronautical monolithic component are studied. Correlated key technologies are also researched. Seven chapters are included in this dissertation.Fundamental concept of distortion correcting is expounded firstly in chapter 1. Then, correcting theory and method with regard to different type of products and structures are summarized. According to the distortion characteristics of aeronautical monolithic components, some key correcting theories and methods are put forward. After that, background and significance of this research is pointed out. Finally, the main contents of this dissertation are summarized.In chapter 2, methods, to distinguish distortion type, to measure distortion value, are presented. Based on the methods, the relationship of several kinds of curvatures that a distorted part must be satisfied during its straightening process is studied. And then, by employing elastoplastic theory, a general expression between bending moment and reverse bending curvature is established when correcting bended distorted part. Considering most aeronautical monolithic components are U-section structure, a new mathematic model for correcting U-section bended part is founded. For operating convenience, a formula is obtained, and it is used to calculate the stroke of pressing down for straightening manufacturing distortion, while the original distortion value and curvature is given. To verify the mathematic model, finite element method is adopted to solve the same problem. The theoretical solution agrees well with the finite element result.For the complicated part, it is almost impossible to calculate correcting parameters by...