Wang, Xiangjiang;Alici, Gursel*;Chuc Huu Nguyen
[Wang, Xiangjiang] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Alici, Gursel] Univ Wollongong, Sch Mech Mat & Mechatron Engn, Wollongong, NSW 2522, Australia.
IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM) - Mechatronics for Human Wellbeing
JUL 09-12, 2013
[Wang, Xiangjiang] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
IEEE ASME International Conference on Advanced Intelligent Mechatronics
Conducting polymer actuators which are capable of operating in air or liquid media under low actuation voltages can be used as macro and micromanipulation devices. However, their positioning accuracy is adversely affected by their hysteresis nonlinearity. In this paper, we establish a Duhem hysteresis model for conducting polymer actuators, which is a rate-independent hysteresis model. The hysteresis model is experimentally identified and integrated with the linear transfer function of the actuator to build a more accurate actuator model.
In this paper, we study the character of solute transport in in-situ leaching of uranium in some sandstone uranium deposit in Xinjiang and analyze the effect of convection, molecular diffusion, mechanical dispersion, adsorption, chemical reaction and radioactive decay on migration and distribution of solute in sandstone uranium deposit. The process of in-situ leaching of uranium in sandstone uranium deposit and shrinkage model of leaching core is divided into 3 interfaces, basic equation of solute transport of in-situ leaching of uranium in homogeneous isotropic sandstone uranium deposit is derived, based on law of mass conservation, the hydrodynamic dispersion coefficient and retardation coefficient of solute transport are determined by analysis-optimization method, the calculated values of solution concentration are consistent with the ones of fitting curve of experimental test values by analysis-optimization parameters and the efficiency of our mathematical model is verified through field test of in-situ leaching.
[Li Guoping] Ningbo Univ, Fac Engn, Ningbo, Zhejiang, Peoples R China.;[Zhang Chunliang] Nanhua Univ, Coll Mech Engn, Hengyang, Hunan, Peoples R China.
IEEE International Conference on Robotics and Biomimetics (ROBIO 2005)
JUL 05-09, 2005
Hong Kong, PEOPLES R CHINA
[Li Guoping] Ningbo Univ, Fac Engn, Ningbo, Zhejiang, Peoples R China.^[Zhang Chunliang] Nanhua Univ, Coll Mech Engn, Hengyang, Hunan, Peoples R China.
active vibration control;bionic mechanics;isolation platform;LQG
Based on the bionics mechanics, a vibration isolation platform is developed. This system uses air springs and rubber layer as passive vibration isolation elements and giant magnetostrictive actuators as active vibration isolation elements. Actuators and air springs are arranged in parallel. The air springs and the rubber layer of the passive system are synthesized so as to minimize the root-mean-square values of amplitude of the isolation platform and the discrete time LQG controller based on a state space model is employed for controlling actuators. Simulation studies show that the developed active vibration control system has good isolation performance against the floor disturbance over wide frequency area. For random or white noise excitation, the amplitude of isolation platform is reduced to approximately 15% by the active control system.
To combat thermal-induced problems such as residual stress, deformation, and crack, induction heating is introduced into weld-based additive manufacturing process as a controlled thermal intervention. To date, however, numerical simulation of this induction-assisted weld-based additive manufacturing process is still a tough task; for conducting transient thermoelectromagnetic motion, coupling analysis is computationally prohibitive. In this paper, a simulation strategy is devised to address the problem. The coupling analysis is performed only at a typical time to obtain the representative distribution of induction heat, which is then transferred to the thermal analysis of multilayer deposition as a moving heat source. Utilizing this strategy, the effects of real-time induction preheating and postheating on residual stress state are analyzed in comparative simulations. The results show that both induction preheating and postheating lead to more homogeneous heat input and lower residual stresses compared with the case without induction heating.
Porous Ti<inf>2</inf>AlN ceramic, which was measured to be 3.23g/cm<sup>3</sup> about 74.9% of its theoretical value, was successfully synthesized and simultaneously consolidated from starting raw materials of Ti, Al, and TiN powders with a near-stoichiometric molar ratio of 1:1.03:1 by a microwave sintering method at 1200°C for 30min in an argon atmosphere. When sintered at 1200°C for 1h, the Ti<inf>2</inf>AlN grain showed a preferred growth behavior along the c-axis in the final ceramic, as shown by the results of an X-ray diffraction study. The Lotgering orientation factor on the surface of as-sintered Ti<inf>2</inf>AlN ceramic was as high as f<inf>(00ℓ)</inf>=0.598. A traditional synthesis method in a quartz tube furnace was also applied to synthesize the materials under the same conditions, but this did not result in similar preferred grain growth phenomenon. Factors affecting the orientation were discussed, and an underlying growth mechanism was suggested. Also, a dense Ti<inf>2</inf>AlN sample was obtained by re-sintering the porous Ti<inf>2</inf>AlN sample using a spark plasma sintering method. As a result, the orientation was maintained, and the density was measured to be 4.21g/cm<sup>3</sup>, which reached 97.6% of its theoretical value.
[Zhu, H. M.; Ringer, S. P.; Liu, Z. W.; Sha, G.] Univ Sydney, ARC Ctr Excellence Design Light Met, Australian Ctr Microscopy & Microanal, Sydney, NSW 2006, Australia.;[Luo, C. P.; Zhu, H. M.; Liu, J. W.] S China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China.;[Zhu, H. M.] Univ S China, Sch Mech Engn, Hengyang 421001, Peoples R China.
This study presents the first experimental evidence of a hydrogen-induced decomposition reaction in an Mg–6Zn–0.6Zr–0.5Cu alloy from combined transmission electron microscopy and atom-probe tomography characterization. The reaction takes place due to the presence of H in the Mg matrix, causes the decomposition of pre-existing, high-temperature Zr–Zn intermetallic rods into Zr-rich hydride and β′ (Zn3Mg2), and forms novel composite precipitates in the Zr-rich cores of the alloy during ageing at 180 °C. The stoichiometry of the Zr–Zn rods was found to be Zn3(Zr1−x, Mgx)2, rather than Zn2Zr3, although both have a similar tetragonal crystal structure. The intrinsic link between the high-temperature Zr–Zn rods and the subsequent elongated composite precipitates, as depicted by the reaction, highlights the importance of engineering the Zr–Zn rod microstructures to control the final precipitate microstructure and effectively strengthen the Zr-rich cores, and hence the advanced Mg alloys.
Zuo Qing-song;E Jia-qiang*;Gong Jin-ke;Zhang, D. M.;Chen Tao;Jia Guo-hai
Journal of Central South University,2014年21(12):4599-4606 ISSN：2095-2899
[Jia Guo-hai; E Jia-qiang; Gong Jin-ke; Zuo Qing-song; Chen Tao] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Zuo Qing-song] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Zhang, D. M.] Calif State Univ Fresno, Dept Ind Technol, Fresno, CA 93740 USA.
[E Jia-qiang] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.