A Study On The Influence Of Cutting Deformation Of Thin-walled Parts Processing Based On FEM

Due to the special requirements of the product function and quality performance, thin-walled parts are widely existed in aviation, shipbuilding and other industries. This kind of structure is most of complex shape that mainly consists of side walls or plate. The outline dimensions of these parts are often much larger than the size of the section, and most need strict flatness and high precision, so that the structure's processing stability and stiffness are very low. Using computer aided engineering(CAE) can effectively alleviate this problem.Firstly, this paper has introduced the characteristic of machining and the key finite element method(FEM), Johnson-Cook plastic model, Johnson-Cook failure model and damage evolution model of ABAQUS/Explicit simulation environment that are widely used in nonlinear thermo-mechanical simulation. Introduced contact characteristics between the tool and work-piece materials and establishing of corresponding friction model in the software.Secondly, this paper has done the simulation analysis of simplified 2D orthogonal cutting and oblique cutting model for the three-dimensional cutting that through using these related methods and technology introduced before, the formation of different morphology chip, the heat and stress–strain problem in the processing. At the same time analyzed the influence of different cutting thickness, cutting speed, cutting angle of cutting force and cutting temperature. So in the other side has verified that this simulation method is feasible by through these works.Thirdly, this paper has done the simulation of three-dimensional cutting model for the simulation of thin-wall plate through those methods introduced before. In this paper, all simulation models are based on isotropic materials and don't take into account the tool wear and deformation, cutting fluid impact. Because of the poor rigidity the thin-wall parts are very easy to produce deformation error in the cutting procession. So this paper analyzed the heat, stress distribution machining error and so on that in the process of cutting of thin-wall parts according to two kinds of constrain conditions models that the “bottom constrain” and the “bottom and two sides constrains”. Through the simulation analysis, compared with the model of “bottom and sides constraints”, only the bottom end of the thin plate constrained model is more prone to produce cutting deformation and dimension error is more sever; The deformation error of thin-wall plate that with “bottom constrain” is decrease that from top to the bottom of the plate and, because of the compound effect of the bending deformation at both side ends and upper end of sheet metal during process, eventually produced a “pit” kind of region in the middle of the thin-wall panel; The plate with “bottom and both sides constrains” has maximum deformation error in the middle region and is decreased gradually from top to the bottom.Finally, this paper simulated and analyzed the cutting of step surface of someone mirror frame. Drawing out the deformation error and compared with the experiment result, the result shows that using ABAQUS/Explicit can accurately and effectively do the finite element simulation for thin-wall parts' cutting machining.