Applied Mechanics and Materials Vols. 401-403

Abstract: Based on the theory of multi-body system, for thetangent method CNC aspheric machine tool, the paper shows out the topologicalstructure and the array of low-order body of the system, the modeling processis stated, a specific mathematical expression for the comprehensive error modelis established, and it will be a steppingstone to the error compensation forthe machine tool.

Abstract: According to the working principle of the ball in and out of the race in inner circulation and external loop, analyzed under the action of axial force of the ball in and out of the influence of the raceway for the ball screw friction resistance, due to ball in rail friction drag is small, that the inner loop no loss as external loop ball friction energy in the circulation pipe, friction torque variation of the ball in and out is small. Experimental results show that the inner loop of the ball screw's friction torque increases with the increase of rotational speed, but the amount of friction torque fluctuation is small, under the screw speed, the axial force has certain influence for inner loop ball screw's friction torque fluctuation and ball impact, but under the relatively high speed is not obvious of on the two.

Abstract: A novel water photovoltaic/thermal (PV/T) solar system was designed, which consisted of a flat plate solar thermal collector and a flat plate PV/T collector in parallel. The area of flat plate solar thermal collector and PV/T collectors were 2m², respectively. The performance of PV/T solar system was tested under condition of flat plate PV/T collectors with glass cover. The test results show that the average output electricity power of PV/T solar system was 28.1W in sunny day at 8:27-17:00 (March 8,2013, at Chuxiong city), the water temperature in the water tank insulation with 200L was raised from 18°C to 60°C. The daily useful efficiency of the PV/T solar system reached 46%. The PV/T solar system could meet the basic need of ordinary families to lighting electricity and hot water. The PV/T solar system had high practicality and was suitable for ordinary rural families.

Abstract: The fatigue rupture is the main form on eccentric axis. Afterwards, make the load function by the eccentric axis and transient dynamics analysis of 4 eccentric axis by ANSYS software. Confirm the dangerous section and nodes. Finally, make fatigue analysis of vibration device with 4 eccentric axis, get the accumulation fatigue factor and get the fatigue life.

Abstract: Analysis impeller axis CNC machining process and processing content, applications Master CAM X6 software to generate a five-axis roughing trajectory of the impeller, the impeller expansion tank and wheels finishing trajectory, blade finishing trajectory. Vericut simulation software tool set, add the tool library, add rough, add impeller machining CNC program, set collision and interference color display, program optimization parameters, simulation of collision-free, without undercutting the five-axis impeller.

Abstract: FAST (Five-hundred-meter Aperture Spherical Telescope) will become the largest single dish ever built in the world. The feasibility of FAST concept, including observatory location, active reflector and feed support has been proven by theoretical analysis and experiments. Results of study indicate that this project is ready to move on to preliminary design. In order to verify the design idea and the key technologies of FAST, the 5-meter experiment model, the 50-m experiment mode and the active reflector model have been designed and constructed. The experiment shows that the feasibility of FAST is been proven by theoretical analysis and experiments.

Abstract: The cracking for the faucet valve made from HPb59-1 brass was investigated by SEM and EDS, metallographic microscope, optical spectrum. The results show that it was a kind of stress corrosion cracking caused by machining stress and corrosive environment (such as sulfur, chlorine etc).

Abstract: An improved helicopter flight dynamic model suited to evaluate the flying qualities of a single rotor helicopter was built for UH-60A, including trim calculation and stability and controllability derivatives. On this foundation, the open-loop flying qualities of the UH-60A helicopter were studied by using MIL-F-83300. According to the requirement, the change of the UH-60A dynamic response and the control characteristics were computed and compared when some typical aerodynamic configuration parameters were adjusted, the influences of the aerodynamic configuration parameters on flying qualities and the sensitivities of flying qualities with respect to the parameters were analyzed.

Abstract: This paper describes a high-performance power-driven design of the permanent magnet direct drive wind turbine. The converter power circuit is designed by AN8026,and the converter drive circuit is designed by HCPL316J,then draw the PCB using the design software Altium Designer Summer 09,create and debug prototype. the final experiment verify that the soft switching power supply can improve the efficiency of the power based on the AN8026,and the drive circuit can increase the reliability of the power module drive based on HCPL316J,so the security and reliable operation of the entire wind power generation system is guaranteed,the switching power supply and drive is especially suitable for the converter hardware system design requirements of the small and medium-sized wind power generation system.

Abstract: Optimal actuator placement is the key technology to be solved for active vibration suppression of large flexible space structure. According to the features of close mode and light damping, the optimal criterion derived from the controllability and observability of Grammian matrix is designed; Hybrid Particle Swarm Optimization (HPSO) algorithm is introduced to solve the problem in optimizing actuator placement, and the detail solving step is given. Compared with genetic algorithm (GA) in previous research, HPSO is better than GA in convergence rates and computing time. Based on the above optimal results, LQG/LTR control method is utilized when the large flexible structure under pulse and Gauss white noise excitation respectively. The numerical simulation results show that LQG/LTR, which has a better performance in suppressing structure vibration than LQG, can suppress the vibration of large flexible space structure and improve system robustness.