Time filter

Source Type

Hao T.,Shanghai Normal University | Yang H.,Shanghai Motor Vehicle Inspection Center | Xu H.B.,Shanghai Normal University
Advanced Materials Research | Year: 2012

A great deal of energy can be absorbed when the inner diameter of a steel tube is inflated by inserting a rigid rod. This procedure has some advantages: high energy absorbed per length, constant compress force and robust to the direction of insertion force. Therefore, this is very fit for energy-absorber for some light vehicles. The effect of energy-absorbing is investigated by impact test and simulation in this paper. Applications for full frontal impact and offset frontal impact of a minibus are discussed. Source

Hao D.,Tongji University | Hou Y.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Ma L.,Tongji University
SAE Technical Papers | Year: 2016

The vehicular fuel cell stack is unavoidably impacted by the vibration in the real-world usage due to the road unevenness. However, effects of vibration on stacks have yet to be completely understood. In this work, the mechanical integrity and gas-tightness of the stack were investigated through a strengthen road vibration test with a duration of 200 h. The excitation signals applied in the vibration test were simulated by the acceleration of the stack, which were previously measured in a vehicle vibration test. The load signals of the vehicle vibration test were iterated through a road simulator from vehicle acceleration signals which were originally sampled in the proving ground. Frequency sweep test was conducted before and after the vibration test. During the vibration test, mechanical structure inspection and pressure maintaining test of the stack were conducted at regular intervals. Experimental results show that the mechanical integrity of the stack remains unchanged, while the gas-tightness degrades obviously. The pressure drop rates of anode and cathode experience a rapid rise at first and then a slow increase to 237 % and 390 % of the original value, respectively. Meanwhile, the rated power of the stack declines by 2.21 % of the initial value. © Copyright 2016 SAE International. Source

Cao J.,Shanghai JiaoTong University | Cao J.,Shanghai Motor Vehicle Inspection Center | Jing L.,China Automotive Technology and Research Center | Guo K.,Shanghai JiaoTong University | Yu F.,Shanghai JiaoTong University
Mathematical Problems in Engineering | Year: 2013

This paper proposes the integrated controller of the yaw and rollover stability controls based on the prediction model. A nonlinear 3-DoF vehicle model with a piecewise linearization tire model is built up as the rollover predictive model, and its accuracy is verified by vehicle tests. A yaw stability controller and a rollover stability controller are proposed, respectively. Then coordinated control strategy is investigated for the integration of vehicle yaw and roll stability controls. The additional yaw torque and braking torque of each wheel are calculated. The unified command of valves is sent combined with ABS control algorithm. Virtual tests in CarSim are carried out, including slalom condition and double-lane change condition. Results indicate that the coordinated control algorithm improves vehicle yaw and roll stability effectively. © 2013 Jianyong Cao et al. Source

Hao D.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Hou Y.,Tongji University | Zhou Y.,Tongji University | Wang H.,China National Institute of Standardization
International Journal of Chemical Engineering | Year: 2016

Based on a review analysis of empirical fuel cell polarization curve models in the literature, an improved model that can predict fuel cell performance with only measured current-voltage data is developed. The fitting characteristics of this new model are validated by fitting bench test data and road test data. In the case of bench test data, a comparison of the new model and two representative models is conducted, and the results show that the new model presents the best fitting effects over a whole range of current densities. Moreover, the fitted ohmic resistances derived from the new model show good agreement with the measured values obtained through a current interruption test. In the case of using road test data, the new model also presents excellent fitting characteristics and convenience for application. It is the author's belief that the new model is beneficial for the application-oriented research of fuel cells due to its prominent features, such as conciseness, flexibility, and high accuracy. © 2016 Dong Hao et al. Source

Hou Y.,Tongji University | Hao D.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Li P.,Tongji University | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2016

The vehicular fuel cell stack is unavoidably impacted by the vibration and shock in the real-world due to the road unevenness. However, influences of vibration on fuel cell stack have yet to be investigated completely. In this paper, the performance of a fuel cell stack is experimentally studied in terms of gas-tightness, voltage degradation, AC impedance spectra, polarization curve and characteristic parameters in polarization curve through long-term strengthened road vibration tests, in order to investigate the influences of road-induced vibration on performance degradation of fuel cell stack. The vibration tests are carried out on a six-channel multi axial simulation table with the vibration excitation spectra originally derived from the strengthened road of the ground prove. During the vibration test, several kinds of performance test including gas-tightness test, AC impedance diagnosis and polarization curve test are conducted at regular intervals. After the vibration test, the gas leakage rate of anode reaches 1.73 times of the initial value. The open circuit voltage and rated voltage decreases by 0.90% and 3.58%, respectively. Meanwhile, the performance of individual cell voltage uniformity becomes worse distinctly. With the increase of vibration duration, the ohmic resistance obtained from AC impedance diagnosis ascends approximately linearly and presents a growth of 5.36% ultimately. An improved empirical fuel cell polarization curve model is adopted to fit the current-voltage data and estimate the characteristic parameters which decide the shape of polarization curve. It is noted that the limiting current density declines distinctly and the mass transfer loss increases mainly at the range of high current densities. The results indicate that the long-term strengthened road vibration condition exerts a significant influence on the durability of fuel cell stack. Copyright © 2016 Hydrogen Energy Publications, LLC. Source

Discover hidden collaborations