Applied Mechanics and Materials Vols. 536-537

Abstract: The thin wall steel U-pipe is the main component of a heat exchanger. It is extremely applied in various machines such as heat exchanger, air conditioner and refrigerator. However, the handicraft operation method is generally adopted in our country currently with its big labor strength and low efficiency in the actual production process. In order to resolve this practical problem, we design the automatic control pipe bender which can process various radius of the thin wall steel pipe.

Abstract: Recently, China has become the country who has the largest and fastest-growing wind power across the world. The large-scale of wind power ask for higher requirements in the fields of Wind Power Plant (WPP) Monitoring and Control. In order to achieve that, the integrated and remote control information system for multi-WPPs is proposed in this paper. To meet the need of technical regulation for connecting WPP to power grid and improve the efficiency of WPP’s management, a framework for this integrated and remote control information system is designed, and some tentative ideas for implementing the integrated control are put forward.

Abstract: Flywheels serve as kinetic energy storage and retrieval devices with the ability to deliver high output power at high rotational speeds as being one of the emerging energy storage technologies available today in various stages of development. This article analyzes the three-dimensional stress distribution of flywheel in Finite-element analysis. It is compared flywheel made of different material to meet the design of reasonable safety composite flywheel.

Abstract: Insufficiency of traditional EB-type silk reeling machine was pointed out after analyzing its traverse mechanism. A novel traverse mechanism driven by non-circular gears with Fourier pitch-line was proposed in order to make up the insufficiency of the traditional EB-type machine. Kinematical mathematic model of this mechanism was established and an aided analysis and simulation software was compiled. A group of preferable parameters was obtained by means of human-computer interactive optimization method. New advantages of uniform roundtrip velocity and better silk winding shape were achieved by the novel traverse mechanism compared to the traditional EB-type mechanism.

Abstract: if the power system is disturbed by a large disturbance, its damping characteristics would change due to the nonlinear factor during the dynamic process and the redistribution of power flow after the accident operation mode. In this paper, the impact of operation mode after an accident and the nonlinear factor for large disturbance dynamic stability of grid are studied respectively. And then, by simulation comparison, it concludes that if nonlinear parts of automatic regulating devices have little impact on the grid damping characteristics after the grid suffers large disturbance, large disturbance dynamic stability of grid is mainly determined by the grid damping characteristics under operation mode after an accident. Finally, conclusions are verified through a practical operation mode of North China Power Grid according to simulation.

Abstract: Development of product innovation design theory, especially the axiomatic design, has changed the pattern depending upon accumulated experience in product design. Independence rule and information rule are the necessary rules of axiomatic design theory. In design of multi-planetary gear transmission, axiomatic design has been applied to determinate type of even-loading mechanism, being important in evenly dividing power into planetary gears to greatly reduce vibration and impact of gear transmission process. By axiomatic design, flexible pin even-loading system and sun gear floating system were compared, and the best scheme has been decided to realize great power transmission.

Abstract: This paper describes design of wheel which can both climb stairs and travel flat ground smoothly. Firstly the corresponding Archimedes helix for climbing a certain size stairs is calculated out. Then arc curve is used to approximate Archimedes helix and the round wheel consisted of circular arc can be converted into similar Archimedes helix vane wheel, enabling the wheel both to climb stairs and to travel flat smoothly. Inventor software is used for mechanism design and modeling.

Abstract: Sand milling collection machinery is a kind of large machinery to collect the surface soil containing ores. The suspension system of milling machines directly affects the ride comfort and driving safety for the operator; for this end, the design of suspension system has been optimized so as to satisfy the requirements of reliability and comfort by making the console and operator set at the maximum station and minimum absolute acceleration and the amplitude within the range. This paper first established a suspension system model of milling collection machines and set up the state equation of suspension system by applying Lagrange equation. On this basis, this paper conducted the optimized calculation encouraged bt the pavement with sine rule change and obtained an optimal suspension system parameters k_i and c_i.

Abstract: Active magnetic bearing (AMB) is a prime component of the more electric aircraft technology that aims at reducing weight and emissions, and augmenting reliability and efficiency for future aircraft. The effect of maneuvering flight on performance of AMB system is investigated. A mathematical model considering maneuver equivalent force is presented and based on the model stability analysis is presented in terms of asymptotical and regional stability. The research result indicts that maneuvering flight has a great influence on system dynamics and stability.

Abstract: For application in large machine tools, the machined part quality, accuracy as well as machining speed depende greatly on the dynamics of the structure. In this paper, an active-excitation modal analysis (AEMA), using inertial force of the moving slider to excite the structural modes, is proposed. Modal parameters of the machine tool structure estimated by AEMA are experimentally validated. Since the artificial excitation produced by elaborate excitation equipment is replaced by the inertial force of the slider, the proposed method is much more practical and economical than traditional methods.