Advanced Materials Research Vols. 1049-1050

Abstract: 3UPU/PU parallel platform is able to achieve a linear and two rotating motion (3-DOF ) platform,it can used in automatic wave compensation of ship deck equipment. The compensation platform is composed of dynamic and static plate, hydraulic cylinder and driven chain parts; it has strong capacity , simple structure and suitable for most conditions. This paper analysis the motion of the platform using one order and two order influence coefficient, establishes the dynamic model of this platform using the Newton Euler method , obtained the velocity, acceleration and force curve by simulating calculation, lay the foundation for the stable platform’s further dynamic analysis and control.

Abstract: In this article the principle of gas squeeze film levitation is described and the main application of it is introduced respectively according to the vibration mode.A new piezoelectric transducer applied for squeeze film bearing which is used for cylindrical shaft and can realize equably circumferential fixed support is proposed, the vibration characteristics of it is studied and the bearing’s loading capacity is tested.

Abstract: In order to solve the problem of the face/core bonding performance of the sandwich structure with chevron folded core, this paper proposed a M-pattern folded sandwich structure. Compression responses of fabricated folded cores were measured, and FE-analytical models were presented to predict the stiffness, strength and dominant failure modes under flatwise loading. The results show that the M-pattern folded sandwich structure has a high anti-buckling performance, and the dominant failure mode of the structure is crushing of the cell walls. The sandwich-panel cores investigated appear to be promising candidates for lightweight systems and multifunctional applications.

Abstract: The internal-mixing twin-fluid atomizer has found wide application in aerospace, industrial gas turbine, oil-fired boiler, energy field and so on. The atomization characteristics of internal mixing nozzle under different operating conditions are studied by utilizing the Malvern laser particle size analyzer. According to the experiment results, the influence of air pressure, hydraulic pressure and air-liquid ratio to droplet size and uniformity are analyzed. The three-dimensional flow field model of internal mixing nozzle is built to simulate the droplet size of mixing room and outlet by Fluent. The simulation results show that the droplet size decreases along with the increase of the air pressure and the air-liquid ratio, moreover, the air pressure plays a main actor. The droplet size increases in the mixing room, and then decrease sharply at the domain of the outlet. The droplet size of the nozzle’s outlet obtained in simulation matches the experimental result.

Abstract: Deployable structures are new prefabricated frames that can be transformed from a closed stage or compact configuration to a predetermined, stable expanded form. The structure is very convenient for transportation and recycling because it can be stretched out, drawn back and disassembled into pieces easily. This paper describes a new deployable structure composed of scissor composite members, each of which consists of universal scissor components, connected by bolts, and braced by pre-tensioned ropes out-of-plane, conforming a stable system. An aluminum-alloy deployable model was fabricated and a test program was carried out under vertical load to evaluate the capacity of the structure. Numerical analysis using FEM was conducted for validation purpose. By studying the stability and capacity of the structure, comprehensive evaluations of the structure were made. Possessing several advantages stated in this paper, deployable structures can be used as semi-permanent and temporary large spatial buildings.

Abstract: For implementing the online control of product development process in Micro-Plant, an integration control platform is proposed based on web service technology. Professional software such as G2, GAMS, Matlab, are wrapped as web services based on multi-agent technology, and the web service named Data_Service is given to implement the data communication among different web services, then we can control and optimize the product development process in Micro-Plant. Finally the practicability and validity of the integration control platform are verified through the application in the product development of Nipagin ester.

Abstract: Searching optimal PID parameters depends on the engineering experience and the experience is more time-consuming, less effective. In order to improve the efficiency of optimizing the PID parameters, propose a method of adaptive particle swarm optimization (APSO) to adjust inertia weight. During searching process, taking PID parameters as particles of particle swarm and the standard of ITAE is the performance index of error. If the algorithm is caught into the local optimal, then change the inertia weight. The simulation on the pitch channel of unmanned powered parafoil shows that the PID parameters of parafoil pitch channel controller which is adjusted by APSO have good effect. At the same time, the result can indicate that the PID parameters adjusted by APSO can improve tracking performance of the system, so that it has highly application value.

Abstract: For implementing the online control and simulation of TE process, a simulation and optimization platform is proposed based on multi-agent technology. Professional software such as G2, GAMS, Matlab, are wrapped as agents with multi-agent technology. Based on the simple object access protocol, it can control and optimize the online simulation procedure of TE process. Finally the practicability and validity of the proposed platform are verified through the application in the TE process simulation and optimization.

Abstract: Since over large starting current makes an instant giant grid voltage drop and contacting with current spark can damage the starting device when three phase asynchronous motor is directly started, in order to reduce the impact on the grid and the motor caused by the over large starting current, the present disclosure provides a frequency conversion soft start system based on SPWN. Control system generates IGBT controlled by SPWM pulse control using the regular sampling II method, thus achieving an AC infinitely approaching to a sine wave to open-loop control the motor and implement soft start. The method of frequency conversion soft start based on SPWM may implement a smooth start of the motor with lesser starting current and larger starting torque, thereby largely reducing the impact on the grid voltage and the motor. The experimental results showed that the method of frequency conversion soft start based on SPWM effectively reduces the starting current and implements the motor’s smooth start.

Abstract: Summary of the development status of combines in domestic and abroad, combined with China's actual conditions, analysis of the problems of combine harvesters, this paper presents the type of combined harvester which suitable for agricultural production in China, put forward rationalization proposals for combine domestic.