Research On Machining Deformation Of Thin-walled Components By Flexible Clamping

Large aeronautical thin-walled components is easy to produce machining deformation due to their large size, low stiffness and complicated structure, and it restricts the development of aviation manufacturing industry for its high manufacturing cost and period,so has always been to seek effective ways to solve this kind of problem. With the continuous improvement of automation level, multi-point flexible tooling system is becoming a hot spot of research, and it can effectively solve the problem of the deformation of large thin-walled components in milling. Has been successfully used in the production abroad, China is still in the stage of research and development and process test.In this paper, according to the need of development of multi-point flexible tooling system, research on the methods to control the deformation of thin-walled parts,and reference to the design of multi-point flexible tooling system.First of all, the cutter model is established by UG software, then import into ABAQUS finite element analysis software.Using finite element analysis software ABAQUS to modeled milling process and multi-point flexible clamping positioning process and accurate definition the finite element model, include the material properties, contact methods, constitutive model,separation criterion and so on.And introduce the basic composition and working principle of the multi-point flexible tooling system, analyze the multi-point positioning principle.Establish the mechanical model of milling processes of aluminum alloy 7050- T7451 through experimental method, which provide the basis to determine the number of support unit. Then,using the finite element method analysis multi-point flexible clamping relative to traditional clamping has obvious advantages, and verify the validity of the finite element model. Then using the finite element method to analyze the influence of clamping force, units layout and units spacing on the deformation of thin-walled;In milling process, to analyze the influence law of clamping force, units layout and spacing on the machining deformation of thin-walled components. Sum up the clamping layout method can reduce effectively the occupy more resources and allocate time.Finally, combining the theory of finite element analysis, the orthogonal experiment and the method of multivariate nonlinear regression, put forward to regard the support units distribute as design parameters, and establish the prediction model put the maximum deformation and the average deformation as a target.In order to simplify the calculation, aweighted way is used to make the multi-objective prediction model into single objective prediction model, Further to treat the single objective prediction model as the objective function, by applying the genetic algorithm to optimize the support units distribution, and gain the optimal layout.