Applied Mechanics and Materials Vols. 321-324

Abstract: Due to the high flow pulsation，the ordinary gear pump has large vibration, noise. A new structure named multi-gear pump was proposed. The model of the pump was established. The motion simulation was given to compare with common gear pump. The simulation analysis show that the pump tooth contact force pulse value is 0.296, which is about 25% lower than the common gear pump. Findings from the paper are supposed to provide a theoretical basis for the following experiments and to improve the life of gear.

Abstract: Solenoid valve is complex heterogeneous system involving multi-physics coupling of mechanics, electronics, magnetics, thermotics, etc, whose reliability and life depends largely on the heat generated during the operation. A multi-physics coupled thermo-mechanics model of a hydraulic proportional solenoid valve used in an automatic transmission was built up with the finite element method (FEM), the temperature and thermal deformation of the solenoid valve with different currents under two operating environments was analyzed. The calculated results show that the operating environment and current are important factors leading to thermal failure of solenoid valves. The model has high accuracy because of considering the multi-physics coupling control characteristics of mechanics, electronics, magnetics, thermotics, etc, and so can be used for the reliability design of solenoid valves.

Abstract: CR-InSAR is developing continuously in recent years. It is an important technology in the field of monitoring crustal micro-deformation. Radar cross section of corner reflector is an important work foundation because only radar cross section of artificial corner reflector achieves maximum, it is easier to recognize it from SAR image and increase monitoring accuracy. Dihedral corner reflector is the simplest type in proving ground of Northwest of Beijing; its RCS research is a beneficial attempt helping to build up reasonable corner reflector layout. In the paper, establishing geometric model and subdivision model of dihedral corner reflector are based on FEKO software, and choosing physical optics to simulate RCS. The simulation result is good consistency with theoretical max value. Through analyzing RCS curve, it can help to provide guidance on how to set up corner reflector in the proving ground.

Abstract: This paper uses the combination between support vector machine and multi-scale principal component analysis. For motor fault detection, the principal component model can be established in various scales. Through T2 and Q statistic judgment whether motor can run normally. The experimental results show that the method of combination vector machine and multi-scale principal component analysis is supported to diagnose motor fault. This offers a new method and idea to diagnose motor. This method improves the accuracy of motor fault detection and practical significance.

Abstract: in order to solve the rainfall simulator single control operation currently used in the experiment of soil erosion. A mobile rainfall simulator was designed. The device adopts a rainfall simulator and Longmen mobile support integration mode, which is controllable and mobile and easy to move. The results show that the equipment is advanced in technology, stable performance, flexible movement, rainfall uniformity high, effective rainfall area is 1.5×4.5m with rainfall intensity ranging from 9.5 to 100mm/h. and to a greater extent meets the needs of rainfall simulation. This rainfall simulator can be used in indoor and outdoor experiment of soil erosion in different slope, which improves the efficiency of utilization of rainfall simulator.

Abstract: The amorphous formation ability, crystallization behavior and magnetic properties of SmCo₇ magnets melt-spun at 30 and 40 m/s have been studied. The ribbons melt-spun at 40 m/s exhibit amorphous structure in the range of 0.15x0.25 for SmCo_7-x(Cr₃C₂)_x alloys. In the amorphous state, these alloys are soft magnetic with intrinsic coercive field _iH_c of the order of 40-70 Oe. After annealing at 750 °C for 5 min, the alloy shows enhenced magnetic properties with _iH_c of 7.98 kOe, M_r of 55.05 emu/g, and M_r of 70.99 emu/g. The MFM image reveals a uniform distribution of individual grains with average size about 20 nm and a domain size about 100250 nm in width. This interaction domain results in the enhancement of the magnetic properties.

Abstract: An experimental study was conducted of reduction of NOx emissions by superfine pulverized coal reburning in Combustion Research Facility (CRF). Based on the systemically measured temperature distributions and analyzed gas samples, the influence of the attention was paid to the superfine pulverized coal reburning characteristic such as NOx emissions, slag formation conditions and mechanical incomplete combustion losses. Experimental results show that feeding pulverized coal for reburning has little influence on the furnace combustion center and slag formation. However, an increase in mechanical incomplete combustion losses was observed in the experiment. In addition, it was shown that the emission of NOx decreased obviously and the reduction efficiency was in excess of 60% with particle size of reburning fuel of 30.74 μm and the proportion of reburned fuel of 14.84%.

Abstract: Cantilever retaining structure is often applied to shallow foundation pit supporting, but it causes large deformation in soft soil region. Reinforcement of soil can solve this problem, and a finite element model of foundation pit which based on elastic fulcrum method is founded to research the regular pattern how the depth and degree of soil reinforcement effects the deformation and the inner force of the cantilever retaining structure. The result shows that the lateral deformation reduces with the increases of the depth and degree of soil reinforcement, and critical depth and degree of reinforcement can been founded. The change of inner force caused by depth and degree of soil reinforcementis small. So it is important to reasonably decide the depth and degree of soil reinforcement.

Abstract: Laser is a coherent, convergent and monochromatic beam of electromagnetic radiation and has wide applications in all walks of life. Surface engineering is one of the applications and contains surface alloying/cladding, surface melting/remelting, surface amorphization and surface hardening/shocking. Laser surface hardening/shocking has been proposed as an effective technology for improving surface mechanical and corrosion properties of metals by inducing a compressive residual stress field. The laser shock processing system with high-energy laser is the key technology for industrial application of surface shocking. The laser shock processing system was described in this paper and the power supply system and the samples gripping and handling system were also introduced. Experiment was conducted by the shock processing system and results shows that high-energy laser has led to compressive residual stress in near-surface regions of 1Cr11Ni2W2MoV stainless steel and improved 1Cr11Ni2W2MoV fatigue life greatly.

Abstract: The XFEM makes research within a standard finite element framework and needs not mesh repartition to geometric and physical interface, and it reserves all merits of the CFEM, therefore it is the most effective numerical method to solve discontinuous dynamic problems so far. The crack growth problem was studied in the XFEM computation, and the displacement mode of elements with cracks and fracture criterion were presented. The numerical examples for steel rod penetrating in the aluminum target concluded that the method and program were reasonable and effective. The crack growth discipline of penetration process for metal material was summarized, and it would establish theoretic base for the further application of the XFEM.