Deformation Monitoring And Adaptive Adjustment Of Feature Machining Sequence Methods For Aircraft Structural Parts

Aerospace structural parts have large dimension, considerable thin-walled structures and large amount of material removal, which is easy to deformation and hard to control. The stress redistribution after releasing clamp may lead to bending, twisting, bending and twisting, etc. The existing processing method is difficult to meet the requirements of controlling the machining deformation. In order to solve the problem, the dissertation focuses on the method of deformation monitoring and adjustment method of feature machining sequence for aircraft structural parts. The research achievements include:(1)A deformation monitoring method based on adaptive clamp was studied. In order to address the problem that the fixed clamp cannot monitor the deformation, a new adaptive clamp method was used, where part deformation is allowed during machining process, the deformation at clamping point is monitored through embedding displacement sensors in adaptive clamps. Considering the needs for monitoring part deformation, the rule of distribution of monitoring points was made, displacement sensors were also used to assist monitoring for the non-clamping points.(2)A strategy of adaptive adjustment for sub-regions’ machining sequence considering machining deformation was studied. The effect of machining sequence on machining deformation was analyzed, considering the rigidity of workpiece in the interim state and deformation monitored, the sub region processing scheduling strategy was established, the machining area was divided by the K-means clustering algorithm, thus to establish the foundation for the adaptive adjustment of feature machining sequence based on deformation monitoring.(3)The feature machining sequence adjustment based on deformation monitoring was proposed. A machining sequence optimization model based on deformation monitoring was established, considering the machining deformation, based on the idea of divide and conquer, orthogonal path method, nearest neighbor method, genetic algorithm were taken respectively to achieve the optimization of the feature machining sequence of features for different regional distribution.(4)A deformation monitoring based adaptive adjustment of feature machining sequence system for aerospace structural parts was developed based on the above research, and it has been validated experimentally and achieved good results.