Yue Ming Liu

Investigation on Key Technology of Virtual Assembly and Construction for Tunnel Boring Machine

This study presents a practical requirement and realizes one new virtual construction interactive system for tunnel boring machine. One type of TBM(tunnel boring machine)’s virtual prototype has been built. Software PROE is used to build the shield machine model. Application program of virtual assembly system base on virtual reality is developed by using Division, The author also study on key technologies of constructing virtual assembly system of shield machine, such as interference detection in virtual environment. Application program of virtual simulation system base on virtual reality is developed by using C++. The result shows that the work station can be simulated well, and this virtual simulation system can be extended in virtual training and manipulation, virtual construction and so on.

The Design and Manufacture of Quick-Point Grinding Wheel

It is important that preparing high quality grinding wheel to match Quick-point grinding processing. Using brazed CBN grinding wheel, grains can be combined with wheel matrix in high bonding strength, which is helpful to minimize wheel wear and to gain a good grinding ability. By establishing the connection between stress and its increment, the mechanical properties of wheel under different conditions is described. The wheel speed has effect on wheel matrix displacement and stress. Applying finite element method to optimize wheel structure, a final grinding wheel for Quick-point grinding is obtained.

The Designing and Wear Simulation of the Wheel Used in Super-High Speed Point Grinding

The application of the wheel used in super-high speed point (SHSP) grinding is introduced in detail, depicting the applied rang of the wheel, through designing the wheel body and the layer of CBN in the wheel. The designed principle is inferred according to the specific shape, the grinding productivity is analyzed in the course grinding zone and the finished grinding zone, introducing the angle of course grinding zone, which affects the grinding parameters in SHSP grinding, the value of the angle is designed to be suited to the point grinding, and manufacturing the wheel, introducing the changed state of chip flowing grinding used in the new wheel, the micro-surface of the wheel is observed through microscope, whose the ratio of air hole and the layer of CBN are analyzed, simulating the wear trend of the new wheel, the conclusions about super hard abrasives and wearing are drawn at last, the application of SHSP grinding is related to designing and manufacturing of the wheel, which provides the equipment for realizing high precision and productivity processing and offers the referred basis for the theoretical research.

Experimental Study of Micro Mill-Grinding Process on Al 6061-T6

This paper presents a novel micro machining process that micro mill-grinding by combining micro-grinding and micro-milling. The principle of micro mill-grinding has been analyzed and a experiment is designed to study the influences in micro mill-grinding process on Al 6061-T6. The manufacturing is carried out on a desktop micro machine developed by NEU. In this research, analysis from results could found that the surface quality influences in micro mill-grinding is complicated affected both by milling and grinding, and conclude aspects such as cutter diameter, feed rate and material properties.

Research on Micro-Grinding Method and Surface Quality

Grinding characteristics brought by the grinding speed reduction and geometrical model differences between micro-grinding and conventional grinding have been mainly researched. Influences which micro-grinding parameter and micro-grinding tool dimension parameter giving to grinding surface quality have been analyzed. The comparison experiment between micro-grinding and micro-milling has been carried out on the micro-machining test-bed developed by Northeast University. Wear of the grinding pin obtained from experiment is considered to provide the basis for the micro-machining system and fabricating of grinding pins.

A Nonlinear Multi-Objective Optimal Design for Cutter Head of TBM

This paper presents a novel model of lay out of cutter head of TBM(tunnel boring machine). Rock-broken mechanism during the operation of the cutter head is analyzed to study the layout of cutters. A model of the cutters under the action of forces during TBM’s working has therefore been developed, thus proposing a scheme to improve the rock breakability of TBM’s cutter head on which the cutters are lay out. Then, a nonlinear multi-objective mathematical model with complex constraints is developed, with an optimization program provided via an intelligent algorithm for the layout design of cutters on the cutter head of a TBM. The cutter head of an EPB6.28 TBM, an optimized design is given to set up a prototype with digitized cutter head, to which a simulation is done for the verification of equilibrium of forces. Comparing analytically the cutter wear and equilibrium of forces between a previous and a newly designed cutter heads, the results shows digitally that the new one is more practicable than the previous one.

Experimental Study on a Micro-Scale Shaft Grinding Tool

This paper presents a novel micro shaft grinding tool is fabricated by cold sprayed with CBN grains, and a micro-grinding experiment is carried out to study micro grinding principle of the fabricated tools. The manufacturing is carried out on a desktop micro machine developed by NEU. Influences caused by particle size on surface quality has been discussed, it has been tested that low surface roughness could be achieved on 3000 particle size of micro shaft grinding tool, the roughness accomplished in the experiment is about 0.086μm.

Study of Micro-Tool Wear Based on Finite Element Method

This paper presents mechanisms studies of micro scale milling operation focusing on micro cutter edge radius. To address this issue, the tool wear model is developed in the present work. Starting with an analysis of the milling edge radius of the tool, the influence of the downscaling on the edge radius is determined by analyzing the milling force. This simulation is used to predict the extent of tool wear in the same milling operation condition by increasing of the tool edge radius. This model accurately predicted the increasing of force with tool wear progress and provides the means for further study of the micro milling tool wear.

A Micro Grinding Experimental Study on AISI 1020 Steel

This paper presents a micro-grinding experiment on AISI 1020 steel to study micro grinding principle. A novel micro shaft grinding tool is fabricated by cold sprayed with CBN grains, the manufacturing is carried out on a desktop micro machine developed by NEU. Influences caused by particle size on surface quality has been discussed, it has been tested that low surface roughness could be achieved on 3000 particle size of micro shaft grinding tool, the roughness of AISI 1020 steel accomplished in the experiment is about 0.086 μm.

Analysis of Roughness in Super-High Speed Point Grinding

The technology of super-high speed point (SHSP) grinding will bring in higher precision and productivity for component manufacturing. The surface roughness attained by SHSP grinding is analyzed in this paper based on the contact area and the probability distribution of chip thickness while the swivel angle of α exists, proposing a new method to predicate the value of the roughness, the experiment of SHSP grinding is carried out whether α exists or not to verify the theoretical analysis in the paper, through observing the micro-surface after grinding, the conclusions will be drawn at last.