Advanced Materials Research Vol. 645

Abstract: Design of the constant current source based on pulse width modulation, and its working principle are discussed. The design can adjust the output current through pulse width modulation (PWM), and realize micro regulation by feedback output which stabilizes current output. The constant current source has some advantages of high precision, stable work, high conversion efficiency.

Abstract: In order to save fuel and reduce emission of Hybrid Electrical Vehicle (HEV), a vehicle control strategy is proposed based on the system efficiency optimal. A vehicle performance simulation model has been built on Matlab/Simulink environment. The results show that, by using this vehicle control strategy, the dynamic performance and fuel economy of the vehicle are significantly improved compared with the traditional one. Finally, The vehicle control strategy has been verified by the bench test.

Abstract: Based on selecting a tunnel collapse under typical conditions of the shallow-buried terrain under unsymmetrical pressure, analyzing the monitoring measurement date, using the software of finite element numerical simulation, the paper simulates the tunnel excavation in lengthwise, deduces the change laws of stress in primary support, the mechanical properties and the collapse mechanism.

Abstract: This paper presentes an interference detection method for workpiece and tool in numerical control machining simulation process.In this method the workpiece is presented by an octree hierarchy sphere model, and outside surfaces of the machining tool are presented by some simple curved surfaces. Using the minimum touching moment between these spheres and surfaces to detect the interference between the workpiece and the machining tool，the judgement problem of the interference in NC simulation is solved. Through this method, the interference judgment becomes convenient and effective after the octree sphere model was established. Finally, we also give an example to explain the algorithm.

Abstract: This paper introduced the application of the loop on the hot strip mill. The loop mainly support the strip steel, form the loop variable which can adjust the dynamic speed of the mill, keep the pulling force of the strip steel between the framework, participate the speed control of the framework of the finishing rolling and the quality of the strip steel is ensured.

Abstract: The thickness of the subgrade model has great impact on the frequency when analyzing the fundamental frequency of the runway by the finite element model, and airport runway under different model of plane will has different influence depth of subgrade. In this paper, an airport runway finite element model, which is base on elastic layer system theory, is established to be loaded different model of plane. The results show that the influence depth of subgrade under different aircraft types, as well as the relationship curves of the influence depth and frequency.

Abstract: Parameters are obtained by mapping the entity structural electronic control unit pump injection system of HXn5 diesel locomotive introduced from USA. A simulation model was built up with GT-Fuel, which can well reflect the electromagnetic and hydraulic characteristics of the fuel injection system, as well as the fuel injection rate and fuel quantity. Compares with locally high-power diesel, the calculation curves show its superiority, which will establish a foundation for optimization and improvement of local fuel injection system.

Abstract: To solve the technology improve of the sintering machine of the steel works of the steel company, the flexible transmission equipment of the planer double-enveloping is designed and manufactured based on the advanced technology of the planer double-enveloping toroidal worm pairs. This paper detailed analysis the flexible transmission principle, the contrast between the original transmission device and the new scheme, the new scheme of the new flexible transmission device, the optimization of the transmission link and the analysis of the structure optimization.

Abstract: In order to understand the dynamic characteristics of 16V240 type diesel, established its solid model and finite element model. And conduct the modal analysis of 16V240 diesel with Lanczos method to get the natural frequencies and vibration mode. And then, find the weak points of 16V240 diesel for its structural redesign and improving.

Abstract: To solve the technology improve of the tundish turning equipment of the steel works of the steel company, the flexible transmission equipment of the planer double-enveloping is designed based on the advanced technology of the planer double-enveloping toroidal worm pairs. the characters of the planer double-enveloping toroidal worm pairs and its research processing are introduced in this paper.