Study On The Key Technologies Of Dynamic Physical Simulation For Machining Process Based On Finite Element Method

New engineering materials appear continually as the technology developing. Each material has marked difference in machining ability. In order to understand farther machining capability of new materials, a great deal of cutting experiments should be carried out. It is a waste of time and money. Besides, many parameters can't be obtained by experiments. So it's highly necessary to find a new reasonable method to study machining capability in place of cutting experiment. Based on this point, the dissertation used Finite element method (FEM) to explore the machining capability of aerospace aluminum alloy 7050-T7451 and titanium alloy Ti-6Al-4V. The machining ability and optimizing cutting process are studied. This provides academic evidence for making technical program.Firstly, based on metal cutting mechanics analysis and simulation experiences which are done before, a two-dimensional orthogonal cutting model is built by FEM for aerospace aluminum alloy 7050-T7451 and titanium alloy Ti-6Al-4V. Constitutive equation and failure equation of material are optimized by experiments. This further improves the precision of finite element simulation model. Based on this simulation model, the influencing regularity of cutting parameters such as cutting speed, cutting depth, rake angle and clearance angle of tool on cutting force, cutting temperature, residual stress and contact length between tool and chip is studied. This can provide evidence for optimizing machining parameters.Secondly, contacting friction between tool and chip is a significant factor of influencing simulation results when using finite element method to simulating cutting process. This dissertation builds five different defining modes of contacting friction between tool and chip. Comparing simulation results of each defining mode, most appropriate mode for defining contact friction between tool and chip is obtained. This can provided foundation for improving model precision.Thirdly, this dissertation simulates multi-cutting process using finite element method. Based on experimental verification, the influencing regularity of first cutting and subsequent cutting to residual stress of finished surface is analyzed. This provides evidence for simulating true cutting process.