Advanced Materials Research Vol. 748

Abstract: Now, Hydraulic tong is an important tool in oil drilling and workover operations. By the structural analysis of open-type hydraulic tong in the new workover hydraulic tong system, doing researchs on the form of the openings in hydraulic tong and the installation requirement of the gears in the open-type hydraulic tong, and to modify the design of the gaps technique about the main tong of open-type, to achieve that the open-type main tong can take a automatic control of the gaps operation.

Abstract: Righting manipulator is imitating the shape of the hand, to replace the worker in the wellhead operations crawl and righting columns action, implemented in unmanned condition wellhead mechanical pipe string centering automatically to a predetermined location function This review focuses on remote control wellhead operations structural design of the righting manipulator, theoretical research, virtual simulation and functional experimental studies.

Abstract: In the manufacturing of large-tonnage forging equipment, heavy and redundant of the body structure components always result in increased manufacturing costs, high energy consumption and performance degradation. Therefore, the lightweight design of machine body becomes one of the important goals in green design of modern forging equipment. Firstly, based on the static and dynamic FEA of YQK-1250 frame hydraulic press body structure, the rational shape optimization results were analyzed through ANSYS Workbench. The thicknesses of the six related ribs were determined as the lightweight targets. Then, a preliminary lightweight optimization is carried out with orthogonal experimental design which provided approximate ranges for the further APDL analysis. Finally the improved lightweight design is optimized by the aide of APDL efficiently. It is validated that the mass is reduced by 4.52% with less influents on the overall performance.

Abstract: The design life of fiberglass pipe is 50 years. In order to ensure long service life of fiberglass pipe, long-term properties under service conditions is the most important performance. According to the polymer matrix composite material with viscoelastic properties, adopt equivalent principle and shift factors method combined with experiments to study the long term performance of fiberglass pipe, established a relatively simple for fiberglass pipes long-term performance prediction method. The experiments show that compliance of fiberglass pipe with all hoop winding increased by 148% after 50 years in 60% stress level.

Abstract: The pipeline’s stability is the key problem of submarine pipeline’s design. In order to supply the theory basis for the pipeline’s design, the ABAQUS software has been adopted to analyze the pipe/soil system. The Ramberg-Osgood model has been adopted to simulate the seabed; the contact pair also adopted to simulate the pipe/soil system, the dynamic boundary contact problem of pipe embedded into the seabed has been analyzed. The computation has been operated according to change pipe’s subweight, environment load, pipe’s diameter, yielding stress and so on. The computation results have shown that these parameters have effects on the pipe’s penetration.

Abstract: This paper gives a low-order approximations of multi-input Volterra series as a nonlinear reduced-order model (ROM) based on wavelet multiresolution analysis. The band-limited pseudorandom multilevel sequence (PRMS) is used as the identification signal and the QR decomposition recursive least square (QRD-RLS) method is utilized as identification method. At last, the ROM is applied to model the nonlinear aerodynamic moment of an airfoil undergoing simultaneous forced pitch and plunge harmonic oscillation. The results show that including the second-order Volterra cross kernels in ROM can capture the coupling effect which significantly improves accuracy in predicting nonlinear aerodynamics under simultaneous motion. And the wavelet multiresolution analysis efficiently reduces the number of identification coefficients for Volterra kernels.

Abstract: The torque vibration derived from in-wheel-motor transmitted to body frame through suspension system without the absorption of mechanical transmission parts, then excited every body panel to shape the vehicle interior noise, which influenced the quality of the vehicle NVH. This paper aims to build an accurate suspension system simulation model to analyze the influence of suspension parts parameters to system vibration transmission property. Basis on a novel empirical model of rubber bushing, a multi-rigid suspension model and a multi-flexible suspension model had been established respectively. The vibration characteristics of two models were simulated, furthermore the swept-sine exciting vertical force signal on wheel contact point were input on the simulation models to find the difference between rigid and flexible model. The simulation results show that: the multi-flexible model can reflect the vibration characteristics of the suspension system more accurately in the high frequency range and so is it more applicable to the simulation analysis of vibration characteristics of in-wheel-motor electric vehicle suspension system.

Abstract: In this paper, the positive steady-state solutions of a strongly coupled partial differential equation system with Holling II functional response is studied. The existence for positive steady-state solutions of system is established by calculating the fixed point index in cone.

Abstract: The application of wind power prediction system (WPPS) contributes to security economic dispatching of power grid and stable operation of wind farm. This paper established short-term prediction model based on BP neural network and ultrashort-term prediction model based on improved time-series algorithm according to Xichang Wind Farm Phase I Project. A new probability model using two consecutive power points before prediction time was built to improve the traditional time-series algorithm. The system framework was designed. C# Language and SQL Server 2008 were taken to develop the system on the Microsoft .net platform. The WPPS uses distributed architecture, realizing seamless connection with the energy management system (EMS) of Xichang dispatching department.

Abstract: In this paper, two multiple feedback loop control schemes for inverters of distributed generators and energy storage system in a microgrid are described. Both of the droop control method and V/F control method are based on the voltage and the current controllers . A detailed comparison of the simulation results show the advantages and disadvantages of the two methods.