FE Simulation Of The Machining Of Aeronautical Light Metal Matrix Composites

The high speed cutting process of particle-reinforced aeronautical light metal matrix composites is a complex thermo-mechanical coupling dynamic problem involving multidisciplinary fields, which includes a series of complicated phenomena such as highly nonlinear, large elastoplastic deformation, high temperature, high strain rate, fracture failure, the collision and friction among particles. At the same time, finite element (FE) numerical simulation has become an important way to study the laws of the cutting process of composites. In this thesis, based on the finite element software ABAQUS/Explicit, the 2D orthogonal cutting microstructural models of metal matrix composites (MMCs) and metal matrix nanocomposites (MMNCs) with two phases are established respectively to get a better understanding of the cutting mechanism and to realize the process optimized design, including constitutive models, failure models, friction models, mesh generation, and so on. By comparing with the experimental results, the reliability of the model establishing method has been validated.In FE modeling, considering that the model complexity increases due to the rise of the nanoparticle number in MMNCs, a second development program is introduced into the models in this thesis on the basis of the Python language in ABAQUS. The random distribution of particles and their cluster phenomenon are realized by this program, which improves the efficiency and accuracy of the models. After the models are established, the process optimized designs for high speed cutting process of the two composites are conducted respectively based on the factor analysis (FA) method. The parameter variables include two kinds, i.e., the material parameters (of the distribution, cross-section, diameter and volume fraction of particles) and the machining parameters (of cutting speed, depth of cut and tool edge radius). By comparing the simulation results of different single factor analysis models, the responses such as Mises stress, chip morphology, machined surface quality and fluctuation of cutting force are analyzed. Then, the multiple factors analysis based on the mathematical statistical software Minitab is carried out, and the influences of different parameters and their coupling effects on a machining response are comprehensively studied. The significance level of each parameter is quantitatively determined finally. Besides, the regression equations of the cutting force are established for prediction. All of the above research work provides a theoretical basis and technical support for the process optimized design in high speed machining of the aeronautical structure composites.