Applied Mechanics and Materials Vols. 543-547

Abstract: Turbine blades crack problem is widespread. Combined with the characteristics of hydropower, analyzes the causes of cracks in the turbine, materials, design and manufacturing, operation and so on. Plant No. 6 in Little Bay machine as an example, were detected by macroscopic, chemical composition analysis, crack cross-section analysis, microstructure examination, crack source electron microscopy and spectroscopy to analyze the crack, the final cause of the crack is leaves the local area resonance, the resonance of the blade in the crater formed at the source of fatigue and fatigue development along at the source, the formation of fatigue cracks.

Abstract: Split Hopkinson Tensile Bar (SHTB) apparatus is widely used in experimentally investigating the mechanical properties of materials. The experimental results are significantly depended on the amplitude, the shape and the wave length of incident wave. However, theres no research on the effect of incident wave especially the influence of parts of the SHTB equipment has been put forward. The solid Hopkinson bar has faced many problems. The hollow Hopkinson Bar has more advantages than the solid Hopkinson bar. The mechanism of the overlying and the amplitude of incident wave by FEM has been analyzed, which can give much help for the theory basis of SHTB apparatus development and design to some extend.

Abstract: This paper describes the development of a full electric vehicle prototype with a new generation of drive-by-wire chassis, which consists of a four independently actuated in-wheel-motor drive system, an electric power steering (EPS) system, an electro-hydraulic brake (EHB) system and a lithium battery energy storage system. This novel electric vehicle called I²EV (I² stands for Intelligent and In-wheel-motor) is designed and tested on a chassis dynamometer to study its performance. Then the road performance of the vehicle is verified through road experiments. These tests clearly show that I²EVcan be employed in further study of intelligent vehicle and advanced integrated chassis control.

Abstract: The combustion characteristics of gas engine are investigated. According to inefficient combustion tendency, prepare solutions, reasonably select supercharging parameters to make estimations and guide the .turbo supercharging matching design of 190 Series gas engine. The design is verified and completed with performance tests, which finally show that the dynamic property of the engine is increased and its economy of is improved.

Abstract: Establish an IPM(Interior Permanent Magnet) motor mathematic model based on saturated inductance parameters. This model aimed at the traction motor of electric drive system of a certain armored vehicle. Driving control system was established on SIMULINK platform, and the consequence was analyzed.

Abstract: Large spaceborne flat seam antennas boom recently. The structure design of the large flat seam antenna is introduced, and finite element model is built. The first frequency of antenna is obtained from modal analysis and it meet the requirement. The results of sine vibration and random vibration shows that strength satisfy the requirement and it has a certain margin.

Abstract: After preliminary design of low floor front axle is finished, finite element analysis module of CATIA is used to calculate the distribution of stress field and displacement field of low floor front axle in the working conditions of vertical static loading, emergency braking as well as side slipping of bus, and then the conclusion will be reached to provide theory basis for front axle design of the whole project.

Abstract: Bringing particle damping technology into the large-scale precise numerically-controlled machine tool will effectively decrease vibration at the time of machinery processing and extend lifetime, and have a wide application prospect on vibration suppression for the precise machine tool. This paper studies the influence of the different density, diameter and filling rate of particle on the structure stability of machine tool. The experimental results show that choosing the proper density, diameter and filling rate of particle has a great influence on practical design and application of precise machine tool, and provides the theoretical basis and design principle for the application of vibration reduction and lifetime extension of the large-scale precise NC machine tool.

Abstract: Applying light structure of railway vehicle car body is the effective way to reduce energy consumption and the dynamic forces between rail and wheel. However, light structure will directly reduce the modal frequency of car body and thus increases the possibility of resonant vibration. It is known that increasing the modal frequency of a fully-equipped car body through structure optimization is barely effective. In this paper, three equations to evaluate the bending frequency of a fully-equipped car body are proposed firstly, then an effective way to enhance the bending frequency of a fully-equipped car body is presented, i.e. elastically suspended the equipment under car body chassis. Also the relations between the suspended mass and the bending frequency are given and validated by means of finite element analysis (FEA).

Abstract: Food is the first necessity of the people, While safety is in the paramount priority of food consumption. The degree of modernization of food machinery is the important sign of weighing a national food industry development level. This paper introduces the status of China's food machinery, analyzes the existing problems and put forward some measures to accelerate the food machinery development. After that, the author is full of confidence on the development prospect of food machinery.