Advanced Materials Research Vol. 645

Abstract: Based on the finite element theory, adopting th e concrete material model which suffers a single vertical earthquake load. The article studies the mode, acceleration time-history curve and stress distribution. The comp arison of theoretical analysis and simulation result shows that the finite element model of the masonry buildings is reasonable and practical. And model is used to the comparison between the reinforcement model and original model in four aspects (model mode, fracture development situation, the acceleration amplification coefficient and the displacement of the wall between windows). Through the analysis, the test result has been supplemented, getting the seismic performance of original model and the increased degree of earthquake magnitude after reinforced.

Abstract: Based on the change of the length for the vibrating-beam, the potential energy stored in the system and the force function are presented. Then the sensor parameters and nonlinear factor are defined and calculated. From this, the mechanical parameters of the vibrating beam can be modeled, and the formulae of the frequency is derived as the function of the external axial acceleration and amplitude, and the mode of a single-degree elastic oscillator is set up. These results are the theoretical bases of developing the vibrating-beam-type accelerometer.

Abstract: Bi-material has been widely used in engineering. Due to the edge singularity, failure usually occurs from interface edge. For the evaluation of such failures, fracture mechanics approach is considered useful to avoid the edge singularity, by introducing an edge crack with various directions. However, this evaluation method is inconvenient for engineering application due to its complicity. In this paper, based on a huge amount of numerical analysis, an empirical formula of stress intensity factors (SIFs) for cracks initiated from the interface edge with various directions and crack length has been proposed. Since the cracks initiated from the interface edge is induced and dominated by the edge singular stress field, which can be characterized by the singular order and the corresponding stress intensity coefficient (SIC), this empirical formula relates their SIFs with the SIC and singular order of the edge singular stress field. With this empirical formula, it is possible to evaluate the fracture occurring from the interface edge by fracture mechanics approach, only with the numerical analysis of non-cracked bonded dissimilar materials.

Abstract: A new intelligent fuze safety system based on a linear piezoelectric actuator is proposed in this paper. The liner actuator utilizes the stator’s first-order longitudinal vibration and second-order bending vibration to drive the slider. According to the initial structure size of fuze safety system, parameter design has been carried out and the actuator’s final size has been determined. The prototype is manufactured and frequency-response experiment shows the two vibration modes can be excited at the same approximately frequency. The speed characteristics of the actuator are measured and the maximum speed of 88.2 mm/s is obtained.

Abstract: This paper represents a fast approach for reduction of torque ripple on brushless DC (BLDC) motor. From a classic motor model, a mathematics component of torque ripple is extracted. To reduce the ripple component, a small modification of PWM and an open-loop control algorithm are made in the inverter of BLDC motor. At last, our paper describes and analyzes the simulation results of this approach by using PSIM. Without any sensors or advanced controllers, this approach can work in most BLDC motor drivers just after software update.

Abstract: Based on the orthogonal experiment, this paper studied the influences of chamfer size on the two-side direction burr in grinding-hardening machine. The results show that: chamfer height size affected the two-side direction burr’s size significantly and the influence of chamfer degree α is general. On this experimental condition, it should adopted grinding parameter ap＝0.2mm,vw＝0.2m/min, the chamfer height h=1.0mm and chamfer degree α=20 o to reduce the two-side direction burr’s size effectively and decrease the workload of removing burr.

Abstract: This study is concerned with the boundary conditions of elastic beams within the framework of nonlocal elasticity th eory. The general solutions of the plane stress problem are, firstly, discussed. Through which and by employing the decaying analysis technique proposed by Gregory and Wan, a set of necessary conditions on the edge-d ata, other than the pure displacement one, for the existence of a decaying solution are formulated. A novel method in constructing the auxiliary regular state is also demonstrated, which is different fr om that we used before. Finally, the appropriate boundary conditions for the interior solution are obtained, which are not altered by the nonlocal parameter and take the form as these for their local elastic counterparts.

Abstract: Application of high-speed on-off valve in the hydraulic speed control system was researched in this paper. The bypass-throttle circuit application of high speed on-off valve is proposed to control the speed of hydraulic cylinder. The duty cycle of pulse control signal was changed according to the displacement of hydraulic cylinder to control the speed and weak the impact. The speed and accelerated speed curves of hydraulic cylinder were achieved by the means of simulation with Simulink and experiment with FESTO is obtained, and research result shows that the applied scheme can effectively control the speed of hydraulic cylinder effectively.

Abstract: Distributed generation technology is a new way of power generation and energy utilization, which has broad prospects for development. After Distributed Generation access to Distribution network near the load, the load distribution will changed.In this paper, discuss the different access location that distributed generation access to the distributed network has different influence to voltage and loss. At the same time, Combination of theory and practical example simulation to description of distributed power generation how to influence the distribution network voltage and network losses. Finally, it’s a brief introduction to the reactive power control strategy of distributed power generation systems.

Abstract: Vehicle power train plays an important role to develop the energy efficient and reduce fuel consumption.In this paper,the drive train fuzzy controller structure and the fuzzy logic control strategies of parallel hybrid vehicles is presented. Simulation results illustrate the potential of the proposed controller and control strategy in terms of fuel economy and in keeping the deviations of SOC at a low level.