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Fan R.,Shanghai JiaoTong University | Fan R.,Hong Kong Polytechnic University | Su Z.,Hong Kong Polytechnic University | Meng G.,Shanghai JiaoTong University | He C.,Zhuzhou Times New Materials Technology Co.
Mechanical Systems and Signal Processing | Year: 2014

In order to provide a quieter riding environment for passengers, sound quality refinement of rail vehicle is a hot issue. Identification of interior noise sources is the prerequisite condition to reduce the interior noise on high speed train. By considering contribution of noise sources such as rolling noise, mechanical equipment noise, structure-borne noise radiated by car body vibration to the interior noise, the synthesized measurement of sound intensity, sound pressure levels and vibration have been carried out in four different carriages on high speed train. The sound intensity and partial coherence methods have been used to identify the most significant interior noise sources. The statistical analysis results of sound intensity near window and floor on four carriages indicate that sound intensity near floor is higher than that near window at three traveling speeds. Ordinary and partial coherent analysis of vibro-acoustical signals show that the major internal noise source is structural-borne sound radiated by floor vibration. These findings can be utilized to facilitate the reduction of interior noise in the future. © 2013 Elsevier Ltd. Source

Jin J.,Zhuzhou Times New Materials Technology Co. | Pan L.,Zhuzhou Times New Materials Technology Co.
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2013

Two different finite element models of one MW composite wind turbine blade were built and the bending stiffness of each section was calculated separately. The cantilever boundary condition were applied to two different models. The first model built a shell model by extruding the outer contour of each section and the second model built a solid model by extruding the plane model of each section. The element coordinate was set accord with the reality layup. The analysis results agree with the foreign technical data schemes, and the availability of method which analyzes the stiffness of blade in different section is verified. It provides references for independent structural design of MW wind turbines. Source

Fan R.,Shanghai JiaoTong University | Meng G.,Shanghai JiaoTong University | He C.,Zhuzhou Times New Materials Technology Co. | Yang J.,Zhuzhou Times New Materials Technology Co.
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2010

With the light weighting trend in railway vehicles and improving requirement for the riding comfort, the control of vibration and noise becomes a more and more important issue. Three types of viscoelastic damping materials, such as bitumen based damping material, water-based damping coating and butyl rubber damping material, are developed and introduced into the studies. Sleeper carriages have been furnished with the new materials in different patterns of free-layer and constrained-layer damping treatment. By comparing vibrations and noise within the running carriages, it is found that bitumen based damping sheet and water-based damping coating are better at reducing noise and vibration than butyl rubber damping sheet. The damping materials decrease vibration components upper and under the car body floor in the whole frequency range. The damping treatments enhance the level of riding comfort for the carriages. The reduction in internal noise and vibration for the former two damping materials increases with increasing travelling speed. The evaluation of the level of internal sound comfort shows that the measure of the loudness is more accurate than A-weighting to indicate how the butyl rubber damping materials influences the internal noise. Source

Tang X.-H.,Zhuzhou Times New Materials Technology Co. | Lu M.,Hunan University of Technology | Feng X.-B.,Zhuzhou Times New Materials Technology Co. | Liu K.,Zhuzhou Times New Materials Technology Co.
Advanced Materials Research | Year: 2012

The weight loss rate, FTIR characteristic, static mechanical properties and dynamic mecha nical properties of neat epoxy resin and glass fiber/ epoxy resin laminates (GF/EP) after thermal-col d cycling were studied in this paper. The rule of static tensile and flexural strength of neat epoxy resi n and GF/EP after ageing was investigated through the static mechanical properties analysis. The age ing mechanism of GF/EP was studied by analyzing the storage modulus (E'), loss modulus (E"), loss factor of GF/EP and FITR of epoxy resin. The results show that the weight loss rate increases with t he ageing time, which is up to 9% after 400 times ageing cycle. The strength and flexural strength of GF/EP decreased by 6% and 21% after ageing, while the tensile strength of neat epoxy resin incre ases by 8% and its flexural strength increases slightly after ageing. The mechanism analysis reveals t hat internal defects of GF/EP would be induced by thermal-cold cycling stress, which results in the i nterface bonding strength dropping and the performance reducing. © (2012) Trans Tech Publications, Switzerland. Source

Yao S.-W.,Beijing Institute of Technology | Zheng X.,Beijing Institute of Technology | Cheng H.-T.,Zhuzhou Times New Materials Technology Co. | Huang Y.-J.,Zhuzhou Times New Materials Technology Co. | Mo R.-L.,Zhuzhou Times New Materials Technology Co.
Journal of Beijing Institute of Technology (English Edition) | Year: 2015

Taking the rubber torsion bushing of a certain type of all-terrain tracked vehicle as the research object, a theoretical model of torsional stiffness was proposed according to the non-linear characteristics of rubber components and structural feature of the suspension. Simulations were carried out under different working conditions to obtain root mean square of vertical weighted acceleration as the evaluation index for ride performance of the all-terrain tracked vehicle, with a dynamics model of the whole vehicle based on the theoretical model of the torsional stiffness and standard road roughness as excitation input. Response surface method was used to establish the parametric optimization model of the torsional stiffness. The evaluation index showed that ride performance of the vehicle with optimized torsional stiffness model of suspension was improved compared with previous model from experiment. The torsional stiffness model of rubber bushing provided a theoretical basis for the design of the rubber torsion bushing in light tracked vehicles. © 2015, Editorial Department of Journal of Beijing Institute of Technology. All right reserved. Source

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