Applied Mechanics and Materials Vols. 271-272

Abstract: The couplings join the various parts together to form an assembly through contact surface, which the stiffness plays an important role for the machine characteristics. Hertz contact theory constructed the relationship between preload and stiffness from a macro perspective, while MB fractal theory presented the mapping between preload and stiffness from microscopic viewpoint. A more precise contact surface model about load and stiffness is established through learning from each other and cross-linking to prepare for analyzing the whole dynamic characteristics.

Abstract: According to the requirements of hydraulic transmission to two-way cartridge valve, and from the practical point of view a water hydraulic two-way cartridge valve was designed. Then its structure characteristics was introduced and the mathematical model was established. The simulation analysis of the water hydraulic two-way cartridge valve has been carried out through Matlab/Simulink proving that its structure was reasonable and it had good performances.

Abstract: Determination of spindle rotate speed of lathe is an important issue when machine tools with changeable spindle gear ratio cutting metal parts, especially in heavy load cutting. Genetic optimization is used to automate design in engineering application for minimizing volume or weight. A quantum genetic optimization method was applied to calculate rotate speed and ratio of spindle transmission for gain maximum motor efficiency in numerical control lathe. Quantum bit code way was applied to simplify calculation and improve compatibility. Rotate angle strategy gate were introduced to Quantum gate for realizing evolution operation. The results were compared with a trial and error procedure usually applied. Quantum genetic arithmetic produced quite well results promptly supplying economic cutting parameters of numerical control (NC) lathe.

Abstract: In an nLDMOS, both the drain-side and source-side engineering by adding N_ad and P_ad layers to obtain a weak snapback characteristic are presented in this work. In this paper, we will detailedly discuss the trigger voltage (V_t1) and holding voltage (V_h) distribution of a novel high-voltage (HV) nLDMOS device. It’s a novel method to reduce the V_t1 and to increase the V_h. Therefore, these efforts will be very suitable for the HV applications in power management ICs.

Abstract: The repairing of incomplete measured data caused by the inaccessibility or invisibility of some portions of the product surface for measure tools plays an important role in Reverse Engineering. The fundamental principles of Reverse Engineering and Anatomical CAD are introduced. The main functional advantages of 3-matic package integrated with Anatomical CAD are presented. There is a big difference in the working flows between Anatomical CAD and traditional CAD packages in the process of RE data repairing. In this paper, we propose a new method of data repairing based on Anatomical CAD. The point cloud of the stamping part obtained by a Potable CMM is repaired successfully by 3-matic, which reduces preparation times by working with a triangular mesh directly, and saves the turn-around time and works more effectively.

Abstract: According to the mechanical seals’ characters of the aircraft engine: no special flush fluid equipment and the limited space etc, a numerical model of conjugate heat transfer between seal rings and seal chamber is presented. And the flow channel and the flow quantity in the mechanical seal are studied, which will affect the heat transfer between the surface of the seal ring and the flush fluid. At last, the studied results are validated by the test.

Abstract: Reasonable and scientific equipment layout design can adequately use the interior space to arrange and divide vehicle equipments, and the practical operation can be convenient, quick and safe. Take the anti-chemical fire engine as an example, the systems analysis method of vehicle equipment layout design especially for fire engine was proposed, and the correlation matrix and net were established according to the correlation table method in order to make sure the importance degree of equipments. Finally, three design options are evaluated, and the result proves that this method is a feasible solution.

Abstract: Reasonable design of hob tip fillet and calculation of modification coefficients were researched to avoid undercutting in this paper. The undercut gears were generated in the virtual environment based on Pro / E software. Meanwhile, parametric finite element models of undercut gear, ordinary modified gear generated by standard hob and modified gear generated by hob with tip fillet radius increased,were founded by APDL (ANSYS Parametric Design Language).The results show that the minimum modification coefficients chosen to avoid undercutting by traditional modification method may not meet the requirements of contact ratio or addendum thickness.While through reasonable design of hob tip fillet, modification coefficients calculated not only avoid undercutting to improve the tooth bending strength but also meet the requirements of contact ratio ε>1.2 and addendum thickness δ>0.25m (module) .

Abstract: Curing process takes play an important role in the selective laser sintering. The advantage and disadvantage of several traditional curing processes was firstly analyzed in this paper. And then the collapse, warping and cracking of coated sand parts in the microwave curing process were studied by experiments and also the solutions was put forward. Using microwave heat to curing coated sand parts is not only high efficiency,energy saving and environmental protection, but also reduced the shrinking and the defect rate of the parts in the curing process.

Abstract: In this paper, cost coefficient is introduced by using the technology of FMECA and FTA, and the DM model is proposed, the parameters of cost function are determined by applying the comprehensive evaluation method, the system reliability correlation model is set up by using copula function. the model is nonlinear programming, and the minimum cost is the goal of the model. The reliability allocation for diesel engine is completed by use of genetic algorithm. Finally, the feasibility and effectiveness of the model are verified through example.