Advanced Materials Research Vols. 328-330

Abstract: Numerical method to simulate the effect of air bubblers on glass melt flow and heat transfer in glass tank furnace is presented in this paper. The numerical simulation is preformed by using Gambit and Fluent software. Results of numerical simulation for glass melt flow and heat transfer with and without air bubbling technology are compared. The roles of stirring air bubblers installed in different locations played are discussed. The results show that mathematical model established in this paper can better simulate the glass melt circulation and heat transfer in glass tank furance, and air bubbler has a significant effect on glass melt circulation and heat transfer, and the best installation locations should be chosen by calculating in order to make full use of the air bubblers. Air bubbling technology will improve the quality of glass obviously if it is used properly. The results obtained can provide reference for engineering design of glass tank furnaces.

Abstract: Based on the previous work of air traffic, a novel indicator— anti-blockage coefficient was proposed. When air traffic was influenced by bad weather or emergencies, this coefficient, building conflict factor, could calculate the transition probability matrix. Then, with discrete time loss queuing algorithm, it could give the degree of congestion.

Abstract: The establishment of FCEV finite element model of the subframe is based on Hypermesh platform, and a new subframe structure is designed in accordance with the stiffness and strength analysis on the original subframe in all conditions. High-strength steel materials are used to optimize the design of this new structure, which result in the optimal size. Through the comparative analysis of the strength, stiffness, mode shape and quality on new subframe and the original one, it is verified that the design of the new subframe is reasonable and feasible.

Abstract: The traditional numerical methods about calculation of bird strike problems are Lagrangian numerical method and Euler method. However, the existence of the finite element mesh distortion and the problem of insufficient accuracy appeared respectively. In this paper, the SPH meshless method applied to simulate bird strike aircraft engine fan, by comparing the simulated data and experimental data to test the accuracy of the simulation about bird hit the fan that is used SPH method .And by comparing the SPH method and traditional methods of bird strike problems in the time step to prove the superiority of the SPH method.

Abstract: The mechanism of shrink fit toolholder has been analyzed through theoretical modeling and finite element modeling. The performance of shrink fit toolholder mainly depends on the interference value that provides enough clamping force. Interference value between tool and shrink fit toolholder includes two separate parts named as initial interference and compensatory interference. Both types of interference and their related influencing factors are described firstly in this paper. The theoretical model for shrink fit toolholder is then developed. Finally, finite element method analysis is carried out to verify the developed theoretical model. The centrifugal force and environment temperature generated in machining process should be specially paid more attention to as the spindle rotation speed grows faster.

Abstract: Linear, conic, cubic, and sine relief curve are compiled and established in MATLAB, on which gear models are built in UG and a new method of establishing relief gear models is proposed in this paper. Based on the theory of elastic, contact method is used on the proposed finite element models of gears by software LS-DYNA. Total contact force of teeth face, contact force of single tooth and equivalent stress on relief gears in different cases are obtained. The results show that contact impact existing in meshing between teeth of gears is ameliorated, contact force of tooth face and equivalent stress is reduced. The effect of cubic and sine relief curve is the best. So dynamic simulation on relief gears has great significance for reducing contact force between teeth faces of gears.

Abstract: Aspheric optical components are widely used as important parts of commercial optical products owing to their desirable properties. The fast growing demand needs urgently efficient and economical fabrication methods. So this paper discussed systematic geometrical models for programming tool path of precision grinding aspheric mould used in batch production. The integrated geometric models and the corresponding machining parameters, such as suitable radius of tools, tool path interval and linear feed were presented based on precision assurance for lower manufacturing cost and higher production. Therefore, it could also provide a reference for NC control software system in other kinds of aspheric surfaces manufacture.

Abstract: Finite difference equations are used for simulation of plate temperature field in roller quenching, and cooling rate in thickness direction is calculated in this paper. Based on improved Maynier model of steel chemical composition and cooling rate, the microstructure constituents and hardness of 30mm thickness pressure vessel steel 07MnNiMoVDR are predicted and calculated with interpolation method. The experimental verification indicates that the simulation results agree well with the experimental ones.

Abstract: The development of complex product system (CoPS) has longer cycle and many factors affecting development quality. Therefore the quality control of development process is very important. This paper analyzes the characteristics of CoPS, discusses the current situation of the research at home and abroad about quality control and quality evaluation of the development of CoPS, proposes 3D model of quality evaluation and assessment. Development of CoPS can be divided into 8 stages: needs / development objective analysis, scheme design, technical design, manufacture (or building) design, manufacturing, overall test, online test, running test. For every assessed stage, third level index are determined based on resource and conditions, technical conditions and management. A structure of assessment index system of development quality of CoPS is proposed.

Abstract: As a modern manufacturing technology, cryogenic cutting technology is one of effective ways to improve machining efficiency of hard-cutting materials.With typical hard-cutting materials 35CrMnSiA and 45CrNiMoV high-strength steel as the research object, the comparison experiment between cryogenic cutting and dry cutting of two kinds of high-strength steels was made in this paper. In the changing cutting speed conditions, the cutting force and the surface roughness of two kinds of cutting were measured in this experiment.By changing the length of cutting stroke, the cutter wear of two kinds of cutting was measured, and a comparison of chip-breaking effects was made in the experiment.The experimental results indicate that the cutting force, surface roughness, and tool wear in cutting 35CrMnSiA and 45CrNiMoV high-strength steel under cryogenic condition are reduced, and chip-breaking effect of cryogenic cutting is improved. This may be attributed mainly to improve the machinability of higth-strength steel.