Influence of Different Modified Gears on the Vibration and Noise of Electric Vehicle Reducer

The tooth profile crowning modification was applied onto paired gears for reducing the noise of an electric vehicle reducer. The simulated gear contact spots are compared before and after modification, and are validated by a contact spot experiment. Based on the rigid-flexible coupling model of the gear transmission system, the time-varying meshing stiffness, time-varying meshing force, and the vibration and noise of the gear pairs with different modified gears obtained by simulating calculation are analyzed. The results showed that the selection of modified gear has a great influence on the modification effect. In the way of tooth profile crowning, it is not advisable to modify the pinion independently, as it may increase the frequency and degree of meshing impact between the helical gear pair, making the transmission become less smooth; while modifying the wheel and pinion at the same time can effectively reduce the time-varying meshing stiffness and force, and the vibration and noise. Also, the optimized gear modification scheme is verified by the noise test.

Abrupt Change of Bandgap Energy in Quantum System of Nanolayer on Silicon Surface

In the quantum system of nanolayer (NL) on silicon, the bandgap energy obviously increases with decreasing thickness of NL, in which the quantum confinement (QC) effect plays a main role. In simulating calculation, the QC effect has been exhibited as the thickness of Si NL changes along with (100), (110) and (111) direction respectively. And the simulation result demonstrated that the direct bandgap can be obtained as the NL with (001) direction is thinner than 10nm on Si surface. However, it is discovered in the simulated calculation that the QC effect disappears as the NL thickness arrives at size of monoatomic layer, in which its bandgap sharply deceases, where the abrupt change effect in bandgap energy occurs near idea 2D-layer. In experiment, we fabricated the Si NL structure by using electron beam irradiation and pulsed laser deposition methods, in which a novel way was used to control the NL thickness by modulating irradiation time of electron beam. The new effect should have a good application on optic-electronic chip of silicon.

Abrupt Change Effect of Bandgap Energy on Quantum System of Silicon Nanowire

In the quantum system of Si nanowire (NW), the energy bandgap obviously increases with decreasing radius size of NW, in which the quantum confinement (QC) effect plays a main role. Furthermore, the simulation result demonstrated that the direct bandgap can be obtained as the NW diameter is smaller than 3 nm in Si NW with (001) direction. However, it is discovered in the simulating calculation that the QC effect disappears as the NW diameter arrives at size of monoatomic line, in which its bandgap sharply deceases where the abrupt change effect in bandgap energy occurs near the idea quantum wire. In the experiment, we fabricated the Si NW structure by using annealing and pulsed laser deposition methods, in which a novel way was used to control the radius size of Si NW by confining cylinder space of NW in nanolayer. It should have a good application on optic-electronic waveguide of silicon chip.

Modeling and Simulation Based on the Hybrid System of Leasing Equipment Optimal Allocation

Modeling of the hybrid system of leasing equipment optimal allocation and its optimal control methods are put forward based on the hybrid characteristics of succession and dispersion. After studying equipment unit’s hybrid automata model (the hybrid and basic structure), the hybrid system facing manufacture demand can be considered as the synthesis of some hybrid and basic structures, which efficiently avoid combination explosion of models due to the increase of systematic scale. On this basis, we study the hybrid and optimal control methods that meet the demand for some equipment and achieve the usage rate maximization. Following that, calculating methods of performance optimization and simulation are put forward based on the first- and second-order subsection linear model. At last, we also have made the numerical simulating calculation on the equipment’s optimal matching of some leasing company.

Study of the Effects of Cutting Parameters on Poly-Silicon Nano Machining

The current status of nanofabrication briefly reviewed, then molecular dynamics model of poly-silicon is founded on micro-nanoscale with molecular dynamics method, in which several typical defects are distributed reasonably. Molecular dynamics simulation of nanocutting process is conducted according to the simulation model. Keeping the other conditions remain unchanged, simulating calculation is made by reasonably changing cutting parameters such as cutting velocity and cutting depth, through which the changes of the morphology structure of workpiece surface,cutting force and system potential energy are observed. The simulation results are compared and studied, then the influence laws of each parameter on morphology structure of workpiece surface, cutting force and system potential energy are analyzed. Based on this, the mechanism of poly-silicon nanomachining is discussed .

Research on Corrosion Diagnostic Model of Grounding Grid Based on Tellegen's Theorem

Grounding grid was considered as a pure-resistor network and its inner information was obtained through limited grounding leads. A set of diagnostic equations was established based on Tellegen’s theorem. Iteration method and Nonnegative Least Squares method (NNLS) were used to solve it. To verify this method, corrosion diagnosis of single-branch and two-branch was simulated. An optimal plan was proposed in the simulating calculation, which diagnosed step by step and added measurement nodes according to the result of each step. This method is able to determine the corrosion position and degree reliably and the optimal plan has higher efficiency and less workload.

Analysis of Kinematics and Dynamics of 3UPU/PU Parallel Platform Used in Automatic Wave Compensation

3UPU/PU parallel platform is able to achieve a linear and two rotating motion (3-DOF ) platform,it can used in automatic wave compensation of ship deck equipment. The compensation platform is composed of dynamic and static plate, hydraulic cylinder and driven chain parts; it has strong capacity , simple structure and suitable for most conditions. This paper analysis the motion of the platform using one order and two order influence coefficient, establishes the dynamic model of this platform using the Newton Euler method , obtained the velocity, acceleration and force curve by simulating calculation, lay the foundation for the stable platform’s further dynamic analysis and control.