Research On The Key Technology Of Fixture Layout Optimization Of An Aviation Joint Structure Parts

The aeronautical thin-wall components have some characteristics like thick wall, largesize, high precision surface, relatively complex shape and low stiffness in common. In millingprocess, the workpiece is very easy to cause deformation which is difficult to ensure themachining precision.According to the existing machining deformation of aviation connectorstructure, this paper is going to systematically study the theoretical prediction and controlmethod of milling deformation of typical aviation joint structures by using theoretical analysis,finite element simulation and mathematical optimization method.This paper mainly contains the following aspects: using the finite element analysissoftware ABAQUS6.11to calculate the typical joint structure milling process and makecomplex coupling model with the characteristics of milling machinery constructionconsidering residual stress, initial stress of joint structure, milling force of thermal stress andclamping stress. Using this model to study the key technologies of element simulation of themilling process of aerospace aluminum alloy materials named7050-T7451,including J-Cmaterial constitutive model, the tool and the workpiece model, the heat conduction equationfriction model, the finite element mesh model and chip separation criterion standard an so on.With this model to analysis the distribution of Mise stress, residual stress, milling temperatureand deformation.This paper construct the best selected method of the clamping position to typical aviationparts. Using genetic algorithm combined with finite element method to establish the objectionmethod based on the minimum of the average deformation, with the a fixture layoutoptimization model including the variable typical aviation joint decision. Throughoutcomparison, the workpiece’s average deformation which using element simulation arebasically the same as the genetic algorithm optimization corresponding fixture layout,whichdemonstrate the effectiveness of the optimization,and provide a positive basis to improve the deformation of the workpiece.