Applied Mechanics and Materials Vols. 423-426

Abstract: Nowadays, the earthquake occurs in a high frequency, and it not only imposes great financial loss on human’s property, but also leads many people to death. And the emergency self-rescued helmet, which is designed for earthquake, aims mainly at protecting the head of people who get stuck in the earthquake. It owns the dustproof mask and a water balloon which connects to the mask. The dustproof mask can be used to avoid suffocating caused by the rising dust, and the water balloon can provide the victims with the nutrients. The helmet carries the electronic equipment which can guide people to self-rescued process in earthquake, play the music to relieve the victims’ pressure and emit the distress signal, and it can raise the possibility of victims’ survival.

Abstract: A safety structure of plate-fin heat exchanger is designed for some special applications to avoid fluid leakage from one fluid side to the other fluid side. A cavity is designed between two channels and a part of cavity volume is filled with good-thermal conductivity material which is divided into a number of columns. For better thermal performance of this structure, distribution of these columns is optimized. Genetic algorithm is used in optimization of distributions, it is effective and the output is better than the simple optimization. The structure in this paper can provide a new feasible structure of secure plate-fin heat exchanger, and the optimization results obtained by using genetic algorithm can provide some guidelines for the optimal designs of heat exchangers.

Abstract: Roller screw pair is the major part of the rope guiding device that used in deep-sea hoisting mechanism. This paper focuses on the contact problems of the roller screw pair. The hoisting mechanism used in the deep sea engineering has the rope with large diameter, sustaining the great rope tension force. So its important to research the contact stress of the roller screw, This paper study the impact of surface hardness of the roller on the performance of the roller screw, sums up the effect of hardness on the bearing capacity of the roller, and provides the theoretical support and references for the designing and application of this new type of roller screw in marine engineering.

Abstract: With the electrolyte in the vicinity of cathode surface being boiling, electrolyte vacuum surface-boiling electrodeposition is a kind of novel electrodeposition technology implemented in a vacuum environment. The development of its apparatus faces more design challenges in comparison with the ones served for the conventional electrodeposition techniques. To development this special epectrodeposition apparatus, two kinds of systems, namely, electrolyte circulation and filtration system driven by film-pressure and gravity, and condensation-collection-backflow system, were come up with, and their details were introduced in this paper. The applications show that the apparatu can meet the requirements of laboratory research and industrial production very well.

Abstract: Autoclave is widely used in the food processing industry. This article expounds a way of heat recovery system. The aim of the system is that after heat exchanging the water energy recycle use. The article also discusses the economic efficiency of the recycling use system, so as to improve the comprehensive benefits of food production enterprises, and to protect the natural environment.

Abstract: We simulated the output torque relation and transient magnetic field for permanent magnet coupling in different states using Ansoft Maxwell 3D software, we can conclude that the design device can obtain large and smooth torque output and be suitable for mine working environment. We tested and verified the conclusion with experiment at the same time,and analysed deviation ,this provided the basis for conformation optimization and function analysis for permanent magnet coupling.

Abstract: This paper proposed a kind of low voltage stress Z-source inverter topology. In the topology, the inductors of Z-source can be connected alternatively in parallel during the time of shoot-through and in series during the other time. Thus the network can obtain a high boost factor with a small shoot-through duty ratio and can decrease the voltage stress across the switch divices greatly. The principle of the topology was analyzed in detail and the simulation experiments was made as well. Simulation results verified the validity of the topology.

Abstract: Three accurate dynamic model of air spring was set up through aerodynamics, fluid mechanics, structural mechanics,engineering thermodynamics, etc. According to the new established bellow-orifice-reservoir model, bellow-pipe-reservoir model and bellow-orifice-pipe-reservoir model, the dynamic characteristics of air spring were calculated under different excitation amplitudes and frequencies. By comparison with experimental results, it shows that the simulation results of the three models and experimental results coincide very well in dynamic characteristics; the bellow-orifice-pipe-reservoir connection type is recommended as the secondary suspension for low frequency excitations; and the bellow-orifice-reservoir connection type is considered effectively for high frequency excitations; the bellow-pipe-reservoir connection type is not recommended to be used as the secondary suspension because of its negative stiffness.

Abstract: In the process of oil and gas well production, tubing connection stand the axial alternating load during open well, shut well and fluid flow. In order to know premium connection seal ability under the loading, two types of P110 88.9mmx6.45mm premium tubing connections which called A connection and B connection are performed with finite element analysis, in which contact pressures and their the regularities distribution on sealing surface are analyzed. The results show that with the increasing of cycle number, the maximum contact pressures on sealing surface of both A connection and B connection are decreased. The decreasing of the maximum contact pressures on B connection is greater than those on A connection. With the increasing of cycle number of axial alternating compression load, the maximum contact pressure on sealing surface of A connection is decreased, and the maximum contact pressure on sealing surface of B connection remains constant. Compared the result, it shows that the seal ability of A connection is better than B connection under axial alternating tension load, while the seal ability of B connection is better than type A connection under axial alternating compression load.

Abstract: The numerical simulation model was established by using numerical simulation tools of FLAC3D, through establishing interface for digging foundation-soil, which can consider mutual effect of digging foundation-soil. Bearing capacities of the digging foundation in slopes is calculated. The affecting factors of the bearing capacity are analyzed. The results show that the bearing capacity has a positive correlation with the distance between the foundation and the slope and has a negative correlation with the slope ratio, which can be expressed as a quadratic polynomial. Nonlinear regression analysis of calculation data are carried out and the fitting formula of the capacity ratio between pile in the slope and pile in the flat is obtained. Finally, the calculation method of horizontal bearing capacity about pile in the slope is developed, which can provide a reference to specification revision and engineering.