Research On Key Technologies For Machining Distortion Safety Correcting Of Aeronautical Monolithic Component

Distortion of aeronautical monolithic component is the common problem, so the distortion correcting of aeronautical monolithic component is necessary. Improper parameters chosen in the correction processing could lead to unexpected distortion so that the components will be discarded as useless. So the problem of safety correcting technologies becomes an important issue. It has great value in academic and engineering area to research the safety correcting technologies of aeronautical monolithic component. A method combining finite element simulation with experiment and theoretical analysis is adopted in this dissertation to research the safety correcting technologies of aeronautical monolithic component.Firstly, based on the state of the art, theories and methods of distortion correcting of aeronautical monolithic component, the research background and measures of safety correcting technologies of aeronautical monolithic component is put forward. The related theories of structural limit analysis and determination methods of limit load are introduced, it can provide theoretical basis for subsequent studies.The load-deflection curves of bending beam and distribution of residual stress are obtained after three-point bending tests of beam, and bending limit load is calculated. Experimental results are compared with the results of finite element analysis in order to verify the accuracy and reliability of FEM simulation results. The relation between springback and apan, cross section dimension and load is obtained by FEM simulation analysis. These fundamental studies can provide references for forecast of aeronautical monolithic component and their reverse bending correction.Based on the studies above, the purpose and significance of safety correcting of aeronautical monolithic component are put forward, and simulation attention problems of distortion correcting are studied. Simulation is done for safety correcting of monolithic frame ratio part. Considering the safety of distortion correcting, the method of reference curves is raised based on finite element simulation that could be used in distortion correcting operation to forecast the effects of distortion correcting and guide the correcting process, then it is verified by experiment. This method has an important application value.The residual stress has impact on safety and reliability in the process of reverse distortion correcting of aerospace monolithic components, stress relief experiments by vibration were made for the components under constraint conditions and the proper VSR parameters were chosen according to the vibration conditions. The mechanism and effects of VSR were studied for the components. The experimental results verified that the VSR could reduce residual stress and has effect in the distortion correcting of deformed components.Finally, systematical summary is given, and future work is put forward.