Papers by Author: Yue Ming Liu

Abstract: In this paper, based on micro wear form, an approach that using protrusion height, average tool angle, blunt area ratio and coated density to describe the wear of abrasive belt is put forward. The method for calculating the above parameters are also introduced. In experiments, we use the profilometer to collect the abrasive belt surface data and draw figures of the above parameters under service time, which indicates that using topography parameters can describe the degree of belt wear. According to parameters changing slope, the abrasive belt service time is roughly divided into two stages, initial wear stage and stable wear stage but no abrupt wear stage. Initial worn stage grains suffer more stress, patterns of wear are mainly severe wear and pull-off, while stable wear stage grains bear less stress and pattern of worn is dominated by mild wear. In addition to that, the other parameters changing trend is agreed and synchronous with protrusion height.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In this paper, effective finite element model have been developed to simulation the plastic deformation cutting in the process for a single particle via the software of ABAQUS, observing the residual stress distribution in the machined surface, the experiment of grinding cylindrical workpiece has been brought in the test of super-high speed grinding, researching the residual stress under the machined surface by the method of X-ray diffraction, which can explore the different stresses from different super-high speed in actual, and help to analyze the means of reducing the residual stresses in theory.

Abstract: 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.

Abstract: Super high-speed point grinding is a good performance grinding with high surface quality due to its low force. To model point grinding forces including swivel angle formed by tilting wheel to the horizontal workpiece axis seems necessary. In this research, a point grinding force model was present, and the point grinding forces are influenced by factors such as grinding depth, wheel velocity, swivel angle as well as equivalent diameter. And then some experimental tests are carried out. It is found that the experimental data was in good agreement with theoretical model.