Applied Mechanics and Materials Vols. 423-426

Abstract: A method of structural optimization for upper beam is proposed in order to satisfy the requirements of high stiffness and light weight of isothermal hydraulic press. Finite element analysis mold is established in ABAQUS by analyzing structural features and load conditions of hydraulic press. When original structure is retained, stiffness and strength of upper beam are checked based on finite element analysis mold. Key factors influencing stiffness and mass are extracted and analysis results are obtained by experiment design. Mathematical model for structural optimization is established by second order stepwise regression model. The goal of structural optimization is to increase stiffness of upper beam while mass is set as constraint. The stiffness of upper beam is increased by 7.04% and its mass remains unchanged basically when structural optimization is finished.

Abstract: The damper plate effect in a hard disk drive is studied using computational fluid dynamics technique. The well known Large Eddy Simulation technique needs high resources for computing power and time. This study presents a steady k-e turbulent model which needs lower resources but can predict the flow effect. The 3.5 inch hard disk drive is modeled with a hexahedral mesh for the computational domain. First, the RMS velocities of the model without damper plate and head stack assembly compared with LES and the transient k-e method are less than 6 %. After that, the damper plate is inserted into the model and the RMS velocity is compared using 4 methods which are LES, transient k-e, steady-transient k-e and steady k-e respectively. The results of k-e are very close to each other. The RMS velocity errors compared with LES rises up to 12.35-13.20 percent in the middle diameter zone, where there is an effect from diverted flow. The steady k-e provides a good computing time with 20 min/100 iterations and can show the trend of the damper plate effect which can be used usefully in future design work for various variables.

Abstract: The purpose of this paper is to analysis the finite element model of joint methods for chassis space frames of vehicles. Common tee-joint often have poor control of dimensional accuracy. The analysis includes the common tee-joint and new joint method. Although the new joint method will increase in weight a little and easily adjust the accuracy of space frame, it will also improve the connection strength.

Abstract: Through-mask electrochemical micromachining (Through-mask EMM) has been being employed to fabricate hole array on metal plate for its some unique merits. A modified double-sided through-mask EMM, in which a composite mask containing inert metal mask and insulation mask with an acute wall angle on the one side, and only insulation mask having an acute wall angle on the other side are used, was proposed to fabricate deep tapered perforations in the thick stainless steel in this paper. The evolving of hole contour was analyzed numerically and some mask artwork parameters were chosen optimally. Experimental results further verified the feasibility to shaped deep tapered perforation.

Abstract: In order to help to design the bogies for vehicle, the morphology, microhardness and SHCCT diagram of SMA490BW high strength weather resisting plate was carried out. The morphology were ferrite and little pearlite and granular bainite of samples at different cooling speed. With the cooling rate increased, the t_8/5 decreased but the hardness increased. The phase content was composed of pearlite, ferrite and bainite at lower cooling rate, but the phase content was totally composed of bainite.

Abstract: Hydraulic supports series guide rod used in mines, a large quantity processing, low precision in the mass. According to field condition, work out mechanical processing, and designed tooling jigs for 3-D. Used a bumper pin and two V-shaped blocks to fix five point position, process hole 1 and hole 2, then used bolt type locator to realize six point full position, rotate the workpiece by 90° to process the third hole; used semicircular turnover type drill template, the drill template frame and the drill shell connect with T-shaped insert. modularized the drill plate; used eccentric wheel drives mobile platen clamping.

Abstract: Packer is one of the main down-hole mining tools in oil field. When setting the packer prone to fracture under tremendous pressure, directly affect the sealing performance of the packer, which affects the process of mining and safety in production wells. The slip was analysised by using the finite element analysis software ANSYS Workbench. When the applied load is 140kN, the slips maximum stress is 230.11MPa, which exceeding the maximum compressive strength of this material. In the fracturing test of the slip packer test model, the test pressure is 186.33kN when slip fracturing, the compressive strength is measured 233Mpa. To optimize the structure of slip, the spacing size of slip tooth were 15 mm, 25 mm and 30 mm. According to the results of finite element analysis, when the spacing size of slip tooth is 30 mm, the distribution of the slip tooths stress and strain tends to uniform. The maximum load is 240kN. This slip structure size is reasonable, and it provides a reference for the optimization design of slip.

Abstract: Motor valve leakage is not easy to detect during using, so it must carry out quality inspection before assembly into gas meter. The quality appraisement of valve mainly relies on switch times before leakage, and pressure difference measurement is better method for leakage judgment. The static pressure leak detection method, reference gas chamber and control program of solenoid valve are key technologies in pressure difference measurement and life measurement. The new type device is designed with hardware and software, such as gas path and pipes, sensor, the solenoid valves of dynamic structure static switching unit, controller, gas pressure regulation system, automatic detection and valve switching process control program etc. Based on support of hardware and software, dynamic flow pipe is separated to static segments which are reference gas chamber and measuring air chambers; and the signal of chambers pressure difference and switch times without leakage are the output result. Switching frequency ratio of solenoid valves to motor valve is 1:5 or 1:10; lower ratio can prolong the service life of solenoid valves.

Abstract: The concepts of fuzzy reliability are introduced, and the model of fuzzy reliability calculation for cylinder liner wear life is set up. A fuzzy reliability calculation example of cylinder liner wear life for vehicle engine with 4 cylinders is given. The different of reliability calculation between the sample reliability and fuzzy reliability are discussed, and point out that the key for fuzzy reliability calculation is to decide the fuzzy range properly.

Abstract: The overall injection mold structure scheme was determined based on the processing analysis of a large LCD TV panel. Specific heating/cooling system and temperature control system aiming for better surface finish were designed. The runner system, which starts from a pin valve hot runner system and turn to cold runner and then to banana-like gates, was obtained. Lifters used for smooth ejection and pulling side cores were presented. The venting system and the material for the cavity plate were introduced. The assembly drawing was shown and the working process of the mold was described at last.