Key Laboratory of Manufacture and Test Techniques for Automobile Parts

Chongqing, China

Key Laboratory of Manufacture and Test Techniques for Automobile Parts

Chongqing, China
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Liao S.-Y.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Mi L.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Shi X.-H.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts
Energy and Fuels | Year: 2011

Following the analysis of the reactive routine of methanol oxidation, a new reduced chemical kinetic mechanism has been developed for investigation of methanol oxidation. The reduced model involves 17 species undergoing 40 reactions and has been validated against a series of experimental measurements. Experimental data from shock tubes, flow reactors, and static reactors showed that, when the temperature is between 823 and 2180 K, the pressure is between 0.005 and 2.0 MPa, and the equivalence ratio is between 0.2 and 2.6, the proposed mechanism can predict the methanol oxidation process quite well. The premixed laminar flame speeds and ignition delay times computed by this mechanism have demonstrated good agreement with the experimental data as well. Moreover, the reactive intermediates and radicals in static reactors, flow reactors, and premixed laminar flames can also been predicted very well, using this reduced mechanism. Compared with other comprehensive mechanisms, the reduced model is validated by more experimental measurements and a large number of reaction steps involved in the base mechanism have been markedly simplified, while its essential features remain. © 2010 American Chemical Society.


Hu J.,Chongqing University | Hu J.,Chongqing University of Technology | Zhang G.,Chongqing University | Xu H.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Li X.,Chongqing University of Technology
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2013

A gear with different finished surfaces was dealt with pulsed electron beam. Experiments of gear bending fatigue strength were complished and contrasted before and after they were dealt with pulsed electron beam for ground tooth surfaces. The microhardness, roughness, topography, organization structure and stress on gear surfaces were measured and their effects on gear bending fatigue strength were analysed and discussed. Experimental results demonstrate that bending fatigue strength of gear with grinding after irradiation is improved 6.1% than that before irradiation in reliability 50%, while that of without grinding is reduced 14% after irradiation than before irradiation in reliability 50%. The bending fatigue properties of gere are influenced greatly by surface processing technology. The ground gear bending fatigue strength of original and electron beam treated are improved 52.2% and 88.2% respectively.


Huang W.-J.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Huang W.-J.,Chongqing University of Technology | Zhang G.-X.,Chongqing University of Technology | Zhang X.-B.,Chongqing University of Technology
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2013

Microstructure, mechanical properties and tribological properties of 7075 aluminum alloy after super-length aging treatment were investigated. The results show that the hardness and strength of 7075 aluminum alloy exhibit double peaks aging features. Although the hardness and tensile strength of the samples under two peak-aging are almost same, the elongation shows certain difference. The friction coefficients of two peak-aged samples are higher than that of as-received sample (non heat-treatment), and shows few change as the load increases, and the friction coefficients of non heat-treated sample display evidently decrease as the load increases. 7075 aluminum alloy displays the transition from mild wear to severe wear, and the wear rates of aging treated sample are obviously lower than those of non heat-treated samples, and the second peak-aged sample shows the lowest wear rate among the experimental samples, as the load increases. The critical load of peak-aged sample for the transition from mild wear to severe wear are distinctly improved comparing with the as-received sample, and the critical load of second peak-aged sample is also higher than that of first peak-aged sample. The phenomenon indicats that the second peak-aged sample possesses the more excellent tribological performance, which might be attributed to the precipitate of uniform and fine secondary phase η'(MgZn2). 7075 aluminum alloy with different heat treatment modes displays the similar wear mechanism: abrasive and oxidation wear are the main wear mechanisms during the mild wear period, adhesion wear and delamination wear are dominate wear mechanisms during the severe wear period.


Ye H.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Ye H.,Chongqing University of Technology | Peng S.,Chongqing University of Technology | Yan Z.,Chongqing University of Technology | Zhang X.,Chongqing University of Technology
Key Engineering Materials | Year: 2013

The mixed powders of 70%Fe and 30%Al were precoated, and Fe-Al intermetallics coatings were produced on an aluminum ZL114A alloy by means of laser cladding. The microstructure and hardness of the coatings are analyzed by using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and microhardness testing machines. The results show that a fine surface quality can be obtained under a suitable process parameter of laser. The laser cladding layers are mainly consisted of phases of FeAl 3, Fe3Al, FeAl with lump-like, granular, equiaxial and needle-like. The highest microhardness of the cladding layer achieved HV614 and raised 5∼6 times in comparison to substrate. © (2013) Trans Tech Publications, Switzerland.


Hu J.,Chongqing University of Technology | Xu H.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Zu S.,Chongqing University of Technology | Gao X.,Chongqing University of Technology
Advanced Materials Research | Year: 2011

For the bending fatigue under the random load condition, the Miner cumulative fatigue theory was analyzed qualitatively. Random amplitude fatigue load spectrum for experiments was compiled according to that gears work under the load with Gaussian distribution load spectrum. Gear bending fatigue was carried out by the method of group test under the conditions of random load on the electro-hydraulic servo testing machine. Then the P-S-N curve of bend fatigue was got under Gaussian distribution load spectrum with particular coefficient of variation. Experiments prove that fatigue life from the result of random luffing amplitude fatigue experiments is lower than that from constant amplitude fatigue experiments, in which the upper limit of fatigue loads is the mean of load spectrum. It will be not reliable to estimate the bending fatigue life of gears that in the actual service. © (2011) Trans Tech Publications, Switzerland.


Xia H.,Chongqing University of Technology | Ding J.,Chongqing University of Technology | Ding J.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Li W.-Z.,Chongqing University of Technology
Advanced Materials Research | Year: 2012

In this work, the displacement instability of thermally grown oxide (TGO) occurring near the surface groove in Fecralloy substrate subjected to multiple purely thermal cycling, has been simulated coupled with crack propagation in TGO layer using finite element method. Due to insufficiency in the traditional criterion of crack opening displacement (COD), a modified COD criterion is employed to model crack propagation in TGO layer as thermal cycles in which the required input parameters are continually modified as thermal cycling based on the calculation result. The comparison between FEA and experimental results shows a good agreement indicating the validity and accuracy of the simulation, which may provide a solution for future works on more complicated case such as in thermal-mechanical cycling. © (2012) Trans Tech Publications.


Hu J.,Chongqing University | Zhang G.,Chongqing University | Xu H.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Xu T.,Chongqing University of Technology
Applied Mechanics and Materials | Year: 2012

Aim at technology of material surface modification with large scale pulse electron beam, the principle of electronic beam processing was analysed. Mechanism for material surface modification with large scale pulse electron beam was discussed. The technique of material surface modification was divided into dealing directly with electron beam and dealing after coating with electron beam. Then the state of art of material surface modification with large scale pulse electron beam was analysed. And existing problems were pointed out and the trend of develop was summaried. © (2012) Trans Tech Publications.


Ding J.,Chongqing University of Technology | Ding J.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Huang X.,Chongqing University of Technology | Zhu G.,Chongqing University of Technology | And 2 more authors.
Advances in Materials Science and Engineering | Year: 2013

As a kind of novel material of high strength and light weight, carbon fiber materials have been widely used in construction industry to repair the damaged bridges improving its mechanical performance. In this work, the reinforced plates made of carbon fiber materials (for short CFRP) are externally bonded to the bottom of concrete beams to enhance load capacity of beams. The strain energy release rates are calculated at the interest crack in concrete beams based on virtual crack closure technology using FEM and are chosen as the criterion to determine whether the mechanical properties of beams are strengthened by being externally bonded with CFRP. The effects of main crack propagation on plain concrete beam, on concrete beam strengthened with CFRP, and on inclined crack are also discussed. The comparison between the beams with and without CFRP shows that the CFRP significantly increases the loading capacity and crack resistance. It also shows that the main crack propagation can reduce loading capacity and crack resistance regardless of strengthening. The experiment observation also supports this. It proves the validity of the method, and it is concluded that in order to increase the loading capacity and crack resistance effectively, controlling over the crack propagation is necessary. © 2013 Jun Ding et al.


Huang W.-J.,Chongqing University of Technology | Huang W.-J.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Lin Q.,Chongqing University of Technology | Guo Y.-J.,Hunan University of Science and Technology | Zhang X.,Chongqing University of Technology
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2010

Effects of heat treatment on microstructure, mechanical and tribological properties of AS41 magnesium alloy were investigated by means of optical microscope, XRD, SEM and wear test. The results indicate that similar microstructure of magnesium alloy as-cast and solid-solutioned and aged is observed, which is mainly composed of α-Mg matrix and second phases (β-Mg17Al12 and Mg2Si), and β-Mg17Al12 and Mg2Si phases are the principal strengthening phases in the alloy. After heat-treatment, the β-Mg17Al12 phase, which was located along grain boundaries as discontinuous net microstructure in as-cast alloy, distributed in grains and along grain boundaries as particle morphology. The size of Mg2Si phase with Chinese script morphology was reduced, and partly formed particles. The ultimate tensile strength and yield strength of AS41 magnesium alloy were improved by 22.1% and 25.7%, respectively, under the optimum heat treatment condition, but the elongation was not significantly affected by heat treatment. The heat-treated magnesium alloy exhibited the lower and stable friction coefficients than those of as-cast magnesium alloy under lower load, and more excellent antiwear properties on the condition of higher load. The mechanism of as-cast magnesium alloy under higher load is delamination wear and abrasive wear, whereas the dominant wear mechanism of heat-treated magnesium alloy is oxidation wear and abrasive wear. The change in microstructure of magnesium alloy before and after heat treatment is responsible for the change of wear mechanism.


Xu F.,Hunan University | Xu F.,Key Laboratory of Manufacture and Test Techniques for Automobile Parts | Sun G.,Hunan University | Li G.,Hunan University | Li Q.,University of Sydney
Structural and Multidisciplinary Optimization | Year: 2013

Crashworthiness of tailor-welded blank (TWB) structures signifies an increasing concern in lightweight design of vehicle. Although multiobjective optimization (MOO) has to a considerable extent been successfully applied to enhance crashworthiness of vehicular structures, majority of existing designs were restricted to single or uniform thin-walled components. Limited attention has been paid to such non-uniform components as TWB structures. In this paper, MOO of a multi-component TWB structure that involves both the B-pillar and inner door system subjected to a side impact, is proposed by considering the structural weight, intrusive displacements and velocity of the B-pillar component as objectives, and the thickness in different positions and the height of welding line of B-pillar as the design variables. The MOO problem is formulated by using a range of different metamodeling techniques, including response surface methodology (RSM), artificial neural network (ANN), radial basis functions (RBF), and Kriging (KRG), to approximate the sophisticated nonlinear responses. By comparison, it is found that the constructed metamodels based upon the radial basis function (RBF, especially multi-quadric model, namely RBF-MQ) fit to the design of experiment (DoE) checking points well and are employed to carry out the design optimization. The performance of the TWB B-pillar and indoor panel system can be improved by optimizing the thickness of the different parts and height of the welding line. This study demonstrated that the multi-component TWB structure can be optimized to further enhance the crashworthiness and reduce the weight, offering a new class of structural/material configuration for lightweight design. © 2013 Springer-Verlag Berlin Heidelberg.

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