Papers by Author: Bang Yan Ye

Abstract: Spin-forming of part with internal tooth is a new technology of the near-net forming in gear manufacturing field. And the main purpose of the parts spin-forming is to shape teeth on the internal surface of blank. In order to improve the forming quality of internal tooth, the effect of roller on tooth height of spline was investigated by processing experiments and finite element simulation. The result indicates that, for full-radius roller, a large nose radius has also witnessed a discernible growth in spinning force and tooth height; considering the uniformity of tooth height distribution of spun part and decrease in forming force, the bio-conical roller is more suitable for this forming process

Abstract: Spin-forming is a new technique for manufacturing the rotationally symmetric component with internal teeth, such as internal spline and gear. In order to optimize the spin-forming process and improve the forming quality of internal spline, the critical issue, the effect of spin-forming process on product formation was investigated by processing experiments and finite element analysis. The result indicates that it is the flow pattern of metal and friction force in the spin-forming that causes forming defect of product; two pass spin-forming helps to improve the homogeneity of deformation for metal with good plasticity; for internal spline forming, a stepped process is a better spin-forming process compared to a non-stepped one.

Abstract: A three-dimensional “fin-groove” composite structure copper current collector was fabricated by micro-ploughing process. 3D and common 2D carbon anodes for lithium- ion batteries were prepared. The electrochemical properties of these electrodes were studied by linear sweep cyclic voltammetry (CV) and charge-discharge (C-D) test. 2D anode showed high contact resistance, high coulombic efficiency but poor cycle performance. In contrast, 3D anode showed the structure superiority in reinforcing bonding force between active materials and copper substrate, improving the conductive environment and alleviating volume changes. It was believed that 3D anode can keep high coulombic efficiency and improve the cycle performance of lithium- ion batteries.

Abstract: In this paper an automatic and intelligent mechanical part library design framework is proposed by utilizing network resources through real-time collaborative design. The proposed framework is based on the client/server network environment, where Web-based scripting language is used for parametric drive design. On the server side, according to the characteristics of parts and data structures, an extensible library of mechanical parts is established for users to use. Graphics data compression algorithms used in the collaborative design are also put on the system's server-side. The proposed framework provides an effective way with information sharing and flexibility for modern mechanical product design.

Abstract: This research aims to improve the method of Mini-pore Drilling superimposed an axis vibration for hard-to-cut material of Austenitic Stainless Steel 1Cr18Ni9Ti, as well as to make it easier for the chips to be discharged. A mathematical model of vibration drilling is presented, and the relationship between the vibration parameters and cutting parameters to generate little and short broken-chips in vibration drilling is investigated, analyzed and verified by experiments. The results show that when the processing parameters meet the conditions given in this article, stable and reliable chip-breaking can be achieved. The results provide a theoretical guidance to achieve chip-breaking in mini-pore vibration drilling for hard-to-cut material.

Abstract: Spin-forming is a new near net-shape forming process for cup-shaped thin-walled inner gear (CTIG). The CTIG spinning was investigated by numerical simulation and processing experiments. The results show that the compressive deformation along tangential direction on the internal surface of part leads to a reduction in root circle of spun part; and the local loading and friction work result in the nonuniform radial deformation on the external surface of spun part. For spin-forming of CTIG with a small number of teeth, the diameter reduction is feasible for improving the forming quality of tooth groove, while the nonuniform radial deformation would cause concaves on external surface of part. For spin-forming of CTIG with a large number of teeth, the diameter reduction is not conducive to removing the part from the mandrel.

Abstract: This paper studies drilling force of pore for hard-cutting material based on theoretical and experimental investigation during pore drilling process. A coupled thermo-mechanical finite element model of metal pore drilling process was established. Some key techniques such as material model, chip separation and damage criteria and dynamic mesh self-adapting technology in the finite element simulation of metal cutting process were discussed in details. The paper simulated dynamically the chip formation of the twist drilling process in which rigid plastic material model was selected for workpieces and thermal rigid models for tools. The results indicate that the proposed finite element model is not only correct but also feasible in the prediction of the variations of drilling force and torque with amount of feed.

Abstract: The import mechanical components and burden part in aeronautic and automobile industry, such as screw shaft, aero-bearing and engine vane etc. are often found fatigue failure cased by their residual stress state on machined surface. Aiming at the problem, this paper presents a new green machining technology by integrating pre-stress cutting and hard machining method. The principle of pre-stress hard cutting of shaft part is introduced together with its implementary process in this paper. Pre-stress loading method on screw shaft is investigated and device for actualizing the process is designed. Experiment of pre-stress hard cutting is carried out for screw shaft with PCBN tool. The experimental results show that by using this method, residual compressive stress is got on machined surface and hence increase the quality and fatigue life of screw shaft.

Abstract: To solve the problems of automotive wheel’ design by using traditional methods, application of finite element analysis in modern automotive wheel design is presented. Then, for example of SU0011-typed aluminum alloy wheel, this paper illustrates in detail the application in its hub structure design, mold design and casting process. By using the ANSYS software, structural design of wheel is optimized according to the CAE results of fatigue strength. In the meanwhile, the casting mold of wheel hub is also designed. Using the ProCAST software, casting process optimization and casting defects elimination can be realized based on simulating the process of filling and solidification of low-pressure casting. Experimental analysis shows that, with the help of finite element analysis, design accuracy and product reliability can be effectively improved and product development cycles can be greatly shorten. So the application has a very good prospect in the automotive industry.

Abstract: Ultra-fine grained chips with higher hardness and strength than bulk can be produced by severe plastic deformation during orthogonal metal cutting. A finite element method was developed to characterize the distribution of stress, strain, strain rate and temperature in the deformation area at different rake angles and cutting velocities. The coefficient of friction in the tool-chip interface is approximately obtained according model of mean coefficient of friction which is based on experiments in any machining conditions. The formation mechanics of ultra-fine grained chip is discussed and effect of rake angle on microstructure of chips is highlighted. The results of experiment and modeling have shown that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity.