Xu Y.,GM china Investment Company |
Hu B.,Chinese Research Institute of GM
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2015
Generation analysis of engine camshaft cover flatness as the complete strategy frame of "Macro to Micro" and "Complex to Simple" was conducted. Based on the data-driven, non-critical factors were excluded and the root cause was found out gradually. Meanwhile, the methodology of exclusion, comparison and data analysis as well as the analysis tool of casting simulation were adopted, which are taken as helpers for problem investigation and problem solving. Finally, it is confirmed that layout of ejected pins is the major influence of flatness. ©, 2015, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.
Lin J.,Beijing University of Technology |
Yang S.-L.,GM China Investment Corporation |
Lei Y.-P.,Beijing University of Technology
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2014
Aluminum alloys have been proved to be the most acceptable material for weight reduction for automobile bodies. Therefore the process to join aluminum alloys to the traditional material such as low carbon steel has to be developed in vehicle body assembly. The methods to join aluminum alloy to steel material, including arc welding/brazing, laser welding, resistance spot welding, and friction stir welding, were collected and discussed in the paper. To help the designer to estimate the joint strength of various methods, the joint strengths and failure modes of steel/Al dissimilar materials joint under static tensile loading were focused on. Moreover, the trend of the joining method for dissimilar materials is also discussed.
Guo H.-M.,Nanchang University |
Zhang A.-S.,Nanchang University |
Hu B.,GM China Investment Co. |
Ding Y.,Nanchang University |
Liu X.-B.,Nanchang University
Materials Science and Engineering A | Year: 2012
Rheocasting by applying limited angular oscillation was reported for AZ91 magnesium alloy, in which the molten metal was rapidly cooled and vigorously mixed during the initial stage of solidification. Microstructure and mechanical properties of treated AZ91 alloy were investigated. Experimental results indicate that the present rheocasting could give rise to significant microstructure refinement and spherical structure evolution. The hardness of the soft α-Mg phase was dependent upon the grain size and followed the Hall-Petch equation. The hardness of microstructure rheocast under oscillation intensity above the level of 0.26rad/s 2 can be predicted by a rule of mixtures (equal strain treatment). Simultaneous increase in both strength and ductility of AZ91 alloy has been obtained. The refinement of α-Mg phase combined with the discontinuity and refined β-Mg 17Al 12 phase is thought to be the main reasons for the improvement of mechanical properties. Possible mechanisms responsible for microstructure refinement were discussed. © 2011 Elsevier B.V.
Xu Y.,GM China Investment Co. |
Guan W.,Shanghai Office of Anycasting Co. |
Ma H.,Shanghai Office of Anycasting Co.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2011
There exist shrinkage hole and gas hole in crack location of a wiper arm head during fatigue testing. Mould design of the produced parts was analyzed by the help of CAE software. The origination of defects was presented, and countermeasures were provided. Optimized design was obtained through modifying mould and simulation to be implemented on the production. Absence of crack was observed through fatigue testing, improving the quality of product.
Wei C.,Huazhong University of Science and Technology |
Zhang J.,GM China Investment Co. |
Yang S.,GM China Investment Co. |
Tao W.,GM China Investment Co. |
And 2 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2015
As for the tailor welded blanks (TWB) of dual-phase steels, heat-affected zone (HAZ) always exhibits significant changes of mechanical properties after experiencing the laser welding process. Hence, the characterization of HAZ mechanical properties is very critical for the accurate forming simulation and service performance of laser-welded blanks. However, it is still difficult to obtain the regional mechanical properties of HAZ because it has a varied transition of microstructures and mechanical properties in a very narrow range (e.g., <1 mm). In this paper, to investigate the regional mechanical properties of HAZ in the laser-welded joints of DP600 steels, an experimental approach was carried out based on the thermal simulation running on the Gleeble machine. The thermal histories of different regions in HAZ during laser welding were simultaneously measured by thermocouples, and then applied for the thermal simulation. The regional characterization of HAZ mechanical properties was realized with the thermal-simulated HAZ specimens. The results show that the thermal histories in weld and HAZ are very sensitive to the distance from the weld centerline, which results in different relevant microstructures and mechanical properties. The tensile strength of HAZ at different locations decreases with increasing distance from the weld centerline, but the elongation has the opposite tendency. The regional mechanical properties of HAZ were also applied to the finite element model of the tensile testing for welded joint by ABAQUS, an elastic-plastic finite element code. And the finite element simulation shows good agreement with the experimental. © 2015, Springer-Verlag London.
Cui W.,Peking University |
Huang Y.,Peking University |
Gao Y.,Beijing Transportation Research Center |
Dai X.,GM China Investment Co.
ICTIS 2013: Improving Multimodal Transportation Systems - Information, Safety, and Integration - Proceedings of the 2nd International Conference on Transportation Information and Safety | Year: 2013
One of the major problems that limits the practical realization of the Intelligent Transportation System is collecting and distributing transportation information rapidly and effectively. Aside from traditional passive means, mobile devices (such as smart phones) could be exploited to collect various types of transportation information from individuals in massive quantities interactively, as well as delivering guidance and navigation signals to the public to achieve purposes like congestion avoidance. This paper proposes a Mobile Transportation Information Service System (MTISS) which integrates client-end applications with SOA-enabled server-end web services. A unified, loosely-coupled and scalable architecture is presented. Then, a prototype on Android platform and Windows Communication Foundation (WCF) is implemented. The key techniques are discussed. Application scenarios and the features of MTISS are addressed. Finally, experiments are conducted to evaluate the overall performance of the MTISS prototype and the results indicate that our system has high usability, scalability and efficiency. © 2013 American Society of Civil Engineers.