Advanced Materials Research Vol. 502

Abstract: The optimization design about hybrid discrete variables is very significant but also difficult in engineering, mathematics for programming and operational research. Aimed at shortages of existing optimum methods, in this paper, according to the search mechanism of differential evolution algorithm (DEA), a new differential evolution algorithm is proposed to complex optimization problem with hybrid discrete variables The dynamic penalty function was constructed. DEA algorithm program with hybrid discrete variables is developed. The computing examples of mechanical optimization design show that this algorithm has no special requirements on the characteristics of optimal designing problems, it has a fairly good universal adaptability and a reliable operation of program with a strong ability of overall convergence and high efficiency.

Abstract: Vertical hammer mill is widely used in food and feed processing factory. It contains the rotor, sieve plate, machine body, feeding device, discharge device, diver device and etc. Traditional design method used two-dimensional drawings to express three-dimensional information of parts, which was abstract and difficult to be modified. This research utilized 3D software Pro/E to carry out three-dimensional designing, modeling, virtual assemble and motion simulation, and used structural mechanics analysis module Pro/Mechanical to carry out finite element analysis of key parts to optimize design of vertical hammer mill. In the designing process designer can easily modify the parameters, and directly observe the shape, location and movement of parts, which can greatly improve the design efficiency and level.

Abstract: The new technological process to form deep hole in relative thin panel by friction heat not only saves material, but also obtains workpieces with high performance. The thermal analysis about friction heat and force about friction forming hole is one of key technology problems. In this paper, the model of temperature field and stress field are observed with LS-DYNA based on dynamic two sliding friction pair coupling model structure, then the temperature changes of the workpiece under different conditions are studied. The mathematical model verified the correctness of the simulation in this paper, and laid a foundation for further research on deep hole process by friction heat.

Abstract: Spin injection efficiency in the ferromagnet/ organic semiconductors system (FM/OSEs) was explored considering the spin dependence of the electric-conductivity induced by spin injection in the OSEs. It is known that the OSEs is spin polarized, once spin was injected from FM layer to OSEs layer. The up-spin polarons and the down-spin polarons have different density. The spin dependence of the electric-conductivity is so induced. In the literature, it was usually supposed that the electric-conductivity in the spin polarized OSEs is spin independent. So, it is crucial to reflect the physics in the spin injection. Our work shows that the spin-dependent electrical-conductivity is one of the significant factors which affect the spin injection efficiency. The spin injection efficiency increases obviously with the rising of the spin-dependent electrical-conductivity in the same spin injection system. And the effect becomes larger, when the polaron proportion increases. Furthermore, the effects of interfacial electrochemical-potential proportion on the spin injection efficiency in the heterojunction are also included.

Abstract: Aiming at relieving processing of annular hob, a applicable method—circumferential relieving method is proposed, this paper describes the principle of relieving processing and implementation method, also proposes a method of computer control, the device which could be mounted on the worktable of hobbing machine to realize circumferential relieving The results showed that method and device proposed in the paper are practicable.

Abstract: Multi-objective optimization of the dynamic gear flowmeter was established by using computer software optimization toolbox. We established the objective function with flow pulsation coefficient minimum and smallest volume of the meter as optimized object, by establishing boundary constraint conditions and performance constraint conditions, choosing proper parameters and initial values, and then we can optimize the design parameters by the help of computer software using optimization function. The optimizing methods can greatly improved the design and optimizing efficiency, which can help us to get the optimal design in the shortest time.

Abstract: In the working process of the two way cartridge valve, deformation and stress are generated by the effect of the changed internal fluid pressures. In this process, the flow of the liquid flowing through the cross section also changes with it. To analyse the stress and deformation distributions of the cartridge valve under the different pressures and the flow analysis in different flow rates and different pressures, finite element method has been used in this paper for analysis and calculation in order to find the structure weak part, the instable flow rate region and the part which hinder the flow rate increased. The results show that: the phenomenon of stress concentration significantly existed in the opening part on the outlet side of the two-way cartridge valve. Under the maximum operating pressure (the maximum working pressure is 31.5 MPa, the maximum flow rate is 4500 L / min), the deformation was larger in the part of girdle. There was nearly no deformation on the upside of the valve body and the stress was less. So, the valve body was the redundant part of two-way cartridge valves. The instable flow rate region was located in the region of the two-way cartridge valve opening across. In the junction of the export of plug-in mounting component and the plug-in mounting block, the flow of liquid was impeded because of its much block and angular structure. The analysis results above have laid a theoretical foundation for the fatigue strength analysis and structural optimization of two-way cartridge valves.

Abstract: Through experimental research on a new-style water-cooled copper burner, the critical width of natural gas for back-fire was determined between 1.5 and 2 mm, which was much smaller than the number given in general reference. The burner was applied on a condensing boiler upside down. The out-flame limits on copper slot, combusting normally and inversely, were determined. The out-flame limits combusting inversely are not quite different from the normal on and they are just little bigger. Within the range 0.6～5.0W/mm2 of thermal intensity of fire port, primary air ratios are in the extent of 1.6～1.4 at out-flame, which is suitable for small domestic gas burner.

Abstract: This paper mainly talks about the structure of new-energy autos batteries’ cooling fan. It gives the reasons for vibration in theory. It also improved the structure of damping pads for vibration absorption by comparing vibration absorption effect of damping pads made of two different kinds of material. In the end, the better-effect structure and material for vibration absorption is selected after the experimental comparison. In addition, the assembly technique is advanced for fan, which left a notable alleviation of vibration.

Abstract: In order to study the influence of projectile structure on the trajectory stability of oblique penetration concrete, this paper designs five kinds of projectile structure including cylinder, stern, tapered tail, cone with 4° and 7°, using LS-DYNA simulation software, the process of five kinds of projectile structure penetration into concrete is studied. Through the analysis of projectile axial resistance, projectile lateral displacement, deflection angle of penetration process and trajectory, it is obtained that the terminal trajectory stability of different projectile structures, from optimal to worse, they are tapered tail, cone, stern and cylinder. It also obtains the projectile lateral displacement and deflection angle of penetration process gradually increase with the increase of oblique angle.