Coupled Thermo-Mechanical Modelling And Experimental Research For Cutting Process

Finite Element Method (FEM) is a numeric calculation method which has developed with the development tide of computer in the beginning of 1960s and centralized multiple disciplines such as elasticity, mechanics, electromagnetic, thermodynamics and computing technique. FEM becomes a general simulation method to resolve logistic equations of different fields step by step in the last several years with its special flexibility, celerity and effectivity. Not only FEM can solve the elastic (linear or nonlinear), elastic-plastic or plastic (steady or dynamic) problems, but also several kinds of problems like field distribution (stationary or transient state problems of flow field, temperature field or electromagnetic field etc.), water pipe, electric circuit, lubrication, noise, and other interaction problems between construction and temperature.Metal cutting process is a typical thermo-mechanical process which goes together with the occurrence of high strain, high strain rate and instant temperature increasing in an absolutely small region. Relative movement between the tool and the workpiece causes the stress distribution change in the micro structure of the workpiece and the heat distribution change on the contact interface. The local high stress would cause the plastic strain and subsequently generate heat. This heat and the heat on the interface induced by friction build the temperature field of the entire cutting zone. This temperature field would influence the stress distribution of the cutting zone on the other way by influencing the material constitutive relationship. In early years, calculation of this kind of complex thermo-mechanical relationship had been limited by computing ability for a long time. So the application of finite element technique in metal cutting industry was not easily seen at that time. In recent two decades, finite element technique was used more and more frequently and played a more and more important role in metal cutting field.This paper analyzes coupled thermo-mechanical simulation related basic theory and resolving method of the essential phases of simulation. Adaptive meshing and split line technology are introduced to develop two different models. Results of maximam Mises stress, maximam temperature, chip deformation index, interfaces maximam temperature are in small relative error of 0.01%. So each kind of modeling method can be selected if necessary. Differential method is hired to predict the cutting forces of machining aluminum alloy thin-wall part, and the radial force is used to simulate the milling deformation. The deformation results are between 0 and 0.03mm, and the connection trace can be explained with the result curves. Residual stresses of the turbine slot component are simulated by software AdvantEdge and the surface residual stresses of 3 points are compared. Results of the comparison are explained on the microscope level. General finite element software Abaqus is used to build a plain strain model of cutting superalloy GH4169 and saw-tooth chip is got. It proves the existing of adiabatic shearing phenomenon and expains the relationship between adiabatic shearing and the brittle breaking. The relation between saw-tooth chip indexes and cutting speed is got at the same time.