Applied Mechanics and Materials Vol. 197

Abstract: This paper analyzes the effects of the swinging NAH(Near field Acoustical Holography) measuring array on measurement of the sound power level of underwater structure. We use the method of sound intensity integral, the method of mean square sound pressure and the method of NAH reversal pressure to calculate the sound power level under certain collection of frequency with measuring surface in different states. We also analyze the relative error of results acquired by those methods, which can help validating the reliability and the error estimate of the results calculated with NAH.

Abstract: The paper aim the remote monitoring system of energy consumption in buildings based on GSM/GPRS by a case, and introduces the system framework, operating mode, transmission technology, equipments and installation requirements, as well as illustrating software composition and function of the data center. The system can reflect classified electricity consumption in monitored buildings correctly. It not only understand situation of energy consumption in real-time, but also offers basic data for further energy auditing and energy efficiency assessment. The conclusion can develop management of building energy consumption and increase the building energy efficiency.

Abstract: In this paper, a superhydrophobic surface was first obtained on plasma sprayed 316L coatings. The influence of particle size distribution of feedstock powder on the microstructure of the prepared coating was investigated. The results show that a wide particle size distribution may lead to a porous coating with a micro/submicro dual scale morphology. The wettability of the porous coating can change from superhydrophilicity to superhydrophobicity through modulating the surface energy. In addition, mechanical durability tests show that the morphology of the prepared coating varies periodically with abrasion time. The successive exposing of fresh layers with similar morphology during abrasion process was proposed to explain this phenomenon.

Abstract: The recovery of energy from the municipal solid wastes (MSW) is an effective process for the large-scale MSW, the mixing and flow of MSW particles on the grate impact the combustion efficiency in combustion chamber. The travel of MSW on the grate depends on the physical characteristics of the solid wastes and the grate properties. The MSW is a more complex and non-homogeneous, so it is difficult to simulate the particle motion by mathematical model based on contact theory. The MSW particle motion model based on the Markov chain of stochastic process for new type forward-reverse acting grate is built and simulated the MSW particle motion in computer by MATLAB 7 in this paper according to the full-scale experiment. The computer simulation and experimental results suggest that the degree of the forward acting grate inclining to horizontal has an effect on the flow and mixing of the MSW particles.

Abstract: It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation of X60 pipeline steel was employed to experimentally simulate the influence of dents and the mechanism of fatigue crack initiation of X60 pipeline steel after per-tension deformation under cyclic loading were investigated. The results indicate that the mechanism of fatigue crack initiation is the typical cleavage fracture characteristics and the cracks mainly initiates from the non-metallic inclusions which was the local brittle fracture materials such as MnS inclusion. With the pre-tension deformation increase, the yield strength of the matrix was increased and the toughness decreased due to the work-hardening effect. With the effects of the non-metallic inclusions larger, the fatigue cracks initiated from the non-metallic inclusions easier.

Abstract: In order to research the effect of process parameters on temperature field evolution in laser remelting coating prepared by plasma spraying on titanium alloy surface，the finite element model of laser multi-tracks remelting temperature field was established based on ANSYS, and remelting temperature field was analyzed. The analysis results show that: under certain scanning velocity and laser spot diameter, too small laser power can't achieve metallurgical combination between coating and substrate; the effect on temperature field of scanning velocity was smaller than laser power; the influence on molten pool center temperature and remelting width of spot diameter is bigger; preheating coating and substrate can be effectively balance remelting process temperature field, thereby reducing the thermal stress and coating cracks appear chance.Through the calculation model can master the evolution of the temperature of lasre remelting process and can provide the theory basis for process parameter selection and optimization.

Abstract: Micro-actuators using giant magnetostrictive material as the core of drive components are becoming more and more widely used in the field of precise micro-actuator. In order to improve the energy transfer efficiency of the micro-actuator, reduce energy losing as heat and improve the working accuracy of micro-actuator.The relationship of pre-compression stress, magnetoconducivity and electromechanical coupling factor has been analyzed in the theory; A reasonable composition form of bias magnetic field has been put out; The relationship between bias magnetic field and electromechanical coupling factor has been analyzed; The configuration and size of coils have been optimized; The relationship between bias magnetic field and electromechanical factor has been discussed and experiments on correlative fields have been accomplished. When GMM is driven by constant magnetic field, measures like optimizing pre-compression stress, configuration and size of coils can be taken to improve giant magnetostrictive energy transfer efficiency and working performance of micro-actuator so that the driving performance can reach the best.

Abstract: Due to the Low Body and Small Door, Driver’s Comfort in the Process of Getting on and Off the Car Must Be Taken into Account when Designing the Car Body. the Research on Driver’s Comfort in the Process of Getting on and Off the Car Is an Important Direction of Vehicle Ergonomics. and it Is Also One of the Important Projects of Man-Machine Engineering Checking at Present. there Are Quantities of Factors Influencing Driver’s Comfort in the Process of Getting on and Off the Car, such as the Relative Position between the Driver’s Seat and the Steering Wheel, Together with the Instrument Panel, the Size Dimension and the Tilting Degree of the Doorframe of One Side of the Car, the Threshold Layout Position of the Front Porch of a Car, the Coordinates of the Point "R".

Abstract: To the illegal stealing problem using strong magnets, the paper studied on the effect of neodymium magnet field on operation of single phase watt-hour meters. The experimental results show that the magnetic field of neodymium magnet increased braking torque of inductive watt-hour meters and caused the negative error, increased starting current， the instrument internal permanent magnet was magnetized, and anomalies of the permanent magnet degaussing can effectively detect electricity theft.