Applied Mechanics and Materials Vols. 121-126

Abstract: With the application of ANSYS finite element analysis software and environmental data in ChengDao oil field, a nonlinear finite element model of suspended submarine pipeline coupled with sea-floor soil is developed. Discarding the traditional and imprecise pipeline model with double clamped or simply supported ends, the model is founded on the theory of elastic foundation beam, in which the nonlinear effect between pipeline and sea-floor soil is considered. Base on the model we developed, the influences of span length and shear strength of soil at the ends of span on the span’s natural frequency are discussed. And the effects of span length, shear strength of soil and current velocity on the dynamic response of span are also analyzed in this paper. The model we developed in this paper fits the actual structure better, and the analysis is instructive for preventing and controlling the suspending of submarine pipeline.

Abstract: According to the combined application of the reverse technology and the rapid prototyping , which is necessary for the complex design and the concept design of part surface, the text firstly introduce the method of gathering reverse data by ATOS measuring system and the technology of blending triangular Bezier surface . Second, it analyses the optimized disposition of method of reverse data which is related to the technology of rapid prototyping . Third, the trial has been done about the interface files generated and linked the device of rapid prototyping and model processing trial.

Abstract: A speed observer which is consisted of the full order state observer and Kalman filter was designed to estimate instantaneous speed in this paper. It utilized full order state observer to obtain load torque and position information, and combining with electromagnetic torque as the input of Kalman filter. Simulation results show that this method can improve the speed detection accuracy of the PMSM servo system.

Abstract: Conventional operation parameter monitoring device for construction machineries can only achieve sound (or light) alarm and control over over-limit status for operation parameters of construction machinery and it can not save any historical data, thus hinders accurate analysis, diagnosis and maintenance of the construction machinery. The operation parameter recorder for construction machinery developed based on industrial control computer and embedded technology can detect, record and manage the operation parameters. The real time fault alarm and historical data analysis can also be realized. The industrial computer, which is core module of this operation parameter recorder, controls the operation parameter acquisition module based on micro-controller ARMSTM32F103 to acquire and condition each operation parameter of the construction machinery. Application software running on the industrial computer processes the operation parameters and carries out alarm and control operations under abnormal conditions for fault protection. The abnormal data shall then be stored for later fault analysis. This operation parameter recorder can record many different types of operation data and has a large storage capacity, so it is applicable to many different types of construction machinery.

Abstract: In order to improve the dynamic characteristics of crossbeam of heavy NC gantry moving boring & milling machine, the ribbed slab structure of beam were analyzed and optimized with the finite element analysis software, and the comprehensive optimization method of the number, size and layout of ribbed slab were putted forward based on the classification of ribbed slab structure. According to the result of the finite element analysis, the internal type and horizontal spacing of ribbed slab are optimized to get the best number, spacing, thickness and height of ribbed slab; Under the required intensity, stiffness and stability conditions materials are distributed reasonably to reduce beam weight which make little deformation and the uniform stress distribution. The comprehensive optimization method study has reference value for ribbed slab structure design.

Abstract: Point-line meshing gear is a new-styled gear characterized by both easy manufacturing and divisibility of involute gears and high strength for contacting between convex and concave tooth profiles of a circular-arc gear. And contact strength of point-line meshing gears has improved by 1~2 times in comparison with involute gears, and bending strength of such gears has improved by approximately 15%, while noise has decreased even by 5～10dB (A). In addition, with the increase of load, noise will decrease by 3~4 dB (A). Only a few teeth or even 2~3 teeth are required for a pinion gear. There are single point-line meshing gears (equivalent to single arc gear), double point-line meshing gears (equivalent to double arc gear) and few-tooth point-line meshing gears, totaling three kinds, which are widely used in reducers for metallurgy, mining, craning, transport and chemical industries. And the three kinds of gears can be converted into soft tooth-flank, medium tooth-flank and hard tooth-flank gears. Here the types, characters, meshing features and dimension calculation of point-line meshing gears are described.

Abstract: The mechanical manufacturing is the most important index to measure national economic hard power, this study forecast machinery manufacturing output of china in 2011 by combination time series model ARMA. Meanwhile its influential factors were analyzed through creating structure model, the results of analysis can not only help us to find the best method for transformation and upgrade of machinery manufacturing, but also avoid risk of financial crisis in the present adverse circumstances that RMB was appreciated constantly in our country.

Abstract: Lithium niobate powders were prepared by mechanochemical treatments using Li2CO3 and Nb2O5 as raw materials. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) were employed to evaluate the morphologies and structures of samples. The mechanism of LiNbO3 formation of the ground mixture samples was discussed. The crystal structure of mixture was collapsed into a disordered structure, which increased with increasing grinding time. At the same time, the specific surface area increase and the bond energy reduction of the mixture occurred. Consequently, high energy ball milling enables increase of the internal energy, reduction of the activation energy, and improvement of the uniform mixing stage, which resulted in direct formation of singal phase LiNbO3 at a low temperature (500°C). However, the temperature must reach 1200°C for the traditional method.

Abstract: A new kind of pressure coordinated control system suite of regenerative braking system for hybrid electric vehicles (HEV) is proposed in this paper on the basis of appropriate transformation on traditional hydraulic braking system with ABS. AMEsim modular simulation platform is used to build a simulation model of the system. Dynamic performances of the key components and system are simulated and analyzed. And the simulation results show the effectiveness and feasibility of the pressure coordinated control system, which lays the foundation of the design and optimization for the regenerative braking system.

Abstract: Based on reliability design theory, by using the Edgeworth series method, and the sensitivity analysis method, the reliability sensitivity of the cylindrical gear pairs with non-Gaussian random parameters are extensively discussed and a numerical method for reliability sensitivity design is presented. The variation regularities of reliability sensitivity are obtained and the effects of design parameters on reliability of the cylindrical gear pairs are studied. The presented method provides the theoretic basis for reliability design of cylindrical gear pairs.