Applied Mechanics and Materials Vols. 727-728

Abstract: With analysis of the phenomenon that clay adsorb to the caterpillar surface, a new idea focused on improvement in the surface topography of caterpillar to decrease adhesion of clay is presented on the basis of inspiration from the biological hydrophobic phenomenon and perspective of bionics. The surface topography with papillary structure of caterpillar surface is designed on the basis of Lotus-leaf-likes surface with analysis of its microstructure in accordance with similarity principle. The new structure could effectively prevent clay from adhering to caterpillar surface. A model of the new structure is also built.

Abstract: The exact solution of laminated Orthogonal Hyperbolic shell of thermoelastic composite is very important to investigate it’s the mechanical properties. Therefore, many studies were completed in this paper. Firstly, the non-homogeneous state equation in generic coordinates is derived for thermoelastic composites including thermal gradient relationships by the basic equations and state space method. Secondly, an augmented dimension constitutive relationship was obtained by combining thermal gradient relationships into constitutive relationships of composite constitutive relationships based on the theory of symplectic variable and precise time-integration with dimension expanding method. Lastly, uniting state space method and the augmented dimension constitutive relationships, a homogeneous state equation which can be solely solved was deduced by eliminating the stresses in plane. The homogeneous state equation can simplify greatly the solution process of the laminated Orthogonal Hyperbolic shell, improve the calculation accuracy. What’s more, it can be discrete straightly in finite element format. So, the homogeneous state equation, derived in the paper, can supply a new method for the exact solution of laminated structures with complicated boundary condition in practice.

Abstract: This paper uses the ANSYS software to analysis the outer arm opening angel(OAOA) and the outer arm arc angle(OAAA) of W-type metallic sealing ring which can effects on the mechanical properties,obtained in that when the OAOA choose from 1.398°to 14.156 °and the OAAA choose from 30.21° to 59.5 °, the mechanical properties of the sealing ring can satisfy the requirement of use. Then using the MOGA optimization algorithm to optimize the design of W-type metallic sealing ring, and find when the OAOA choose 3.39°and the OAAA choose 32.18°are the optimal design of the W-type metallic sealing ring.

Abstract: In view of the cooling of Insulated-gate bipolar transistors (IGBTs) in the parallel DC boost chopper, this paper presents a method to calculate the power loss of IGBTs. It involves functions of equivalent heat circuit of liquid cooling system based on the similarity theory, and the design of the parameters in the cooling system for DC boost chopper. It solves the problems of parameters designing of liquid-cooled heat sink. Taking the cooling system of IGBTs as an example, the experiment shows that the cooling system based on this method has excellent performances in the worksite, and the method is practical and effective.

Abstract: Hollow thin-walled high pier is a common form of high pier in mountainarea, so it is of practical significance to the dynamic stability analysis ofhollow thin-walled high pier in mountain area. This paper is taking themountainous area of a hollow thin-walled high pier as the background, and theestablishment of the fiber model with Midas for dynamic elastic-plastic timehistory analysis. The results show that: the hollow thin-walled high pier underthe impact load, load amplitude is lower than the critical load,and the dynamic response characteristics of thestructure of the value parameter i.e. horizontal displacement at pier top increaseslinearly with the load amplitude. When the load amplitude is larger than thecritical load, the horizontal displacement of pier top increases with theincrease of load amplitude nonlinearly. Power under dynamic load instabilitycritical load is about 80% under static load.

Abstract: In recent years, civilbuilding photovoltaic system develops very soon in China. But it still in its infancystage and it is urgent to formulate and perfect the photovoltaic standardsystem for different climate zones and construction type. Aiming at thecharacteristics of northeast area of sunshine, we analyze the principle andmethod for photovoltaic system design of civil architecture, developed abuilding rooftop photovoltaic system in this paper. On building in the area ofelectrical system design, simulation of photovoltaic use PVSyst, and thephotovoltaic power generation system simulation results in northeast area ofbuilding roof is obtained.

Abstract: In recent years, energy and environment problems are becoming more andmore serious, become people present and solve the energy crisis in the futurean important way of effective development and utilization of solar energy.Independent photovoltaic system is an important form of effective utilizationof solar energy. On the independent photovoltaic system research andoptimization design is of great significance for the effective use of solarenergy in the future. This paper takes Jilin Province Household independentphotovoltaic power generation system as an example, by using the design methodof the traditional formula and LOLP arithmetic design method are the design ofthe system, the simulation results of PVsyst analysis and comparison of thedata, obtained by LOLP arithmetic design in photovoltaic panels, power andstorage battery capacity is more reasonable, can to meet the needs of users ofthe premise, reduces the investment cost, improving the utilization rate of theequipment.

Abstract: In high load-carrying bearing-rotor system, bearings’ places usually change for load distribution or in continual work. It influences the system’s stability, and brings out different vibration response in rotor system. This article puts forward mathematical model of bearing’s stiffness under load which is calculated from bearing displacement. Then through numerical integration it studies system’s rotating vibration with different bearing settings. The results of the analysis show that bearing displacement has a great effect on dynamic characteristics of the bearing-rotor system.

Abstract: Recently, there have been growing concerns on ships, one of the means to transport plant facilities, as studies on developing large scale plant facilities have been carried out. Particularly, carbon dioxide system, one of the fire safety systems, is mainly used as the fire safety facility of ships, and main valves are employed for supplying carbon dioxide. However, studies on main valves used in ships are yet to be carried out more. Especially, when carbon dioxide is sprayed as a main function of main valves at lower pressure than required, firefighting is put into difficulty. Accordingly, to solve such problem, this study observed internal pressure change using flow analysis of the main valve, then conducted fluid-structure interaction analysis based on its result, and finally investigated disk’s opening and closure and the structural safety and characteristics depending on valve’s inlet and outlet diameters.

Abstract: The stress distribution and modal behavior of a space inflatable torus was investigated by nonlinear finite element numerical method. This paper focused on the effect of follower pressure on the modal analysis of the torus, including the effect of configuration change and follower pressure stiffness, and focused on validating the follower pressure stiffness FEM model and its applicability to modal analysis. Research shows that the changed configuration slightly increases the natural frequencies. The follower pressure stiffness significantly reduces the natural frequencies and changes mode shapes order. The modal results are in good agreement with the corresponding shell theory solutions, indicating that the finite element model of the follower pressure stiffness for the inflatable structure modal analysis in this paper is accurate enough and reasonable.