Entity

Time filter

Source Type


Wu H.,Central South University | Wu H.,Dartmouth College | Baker I.,Dartmouth College | Liu Y.,Central South University | And 3 more authors.
Intermetallics | Year: 2013

In the present study, the tribological behavior of a Zr 52.5Cu17.9Ni14.6Ti5Al10 bulk metallic glass (BMG) was investigated using pin-on-disk sliding measurements under an argon atmosphere, rubbing against a type 303 stainless steel counterface. The tested pins and disk were examined using X-ray diffractometry, optical microscopy, profilometry, scanning electron microscopy and transmission electron microscopy. The results showed that the wear of the BMG pins was substantially larger compared with previous tests performed against a zirconia counterface. Strain softening was found in the near-surface region of the glassy pin due to the highly localized shearing. Frictional heating contributed to the occurrence of viscous flow and material transfer on the worn surface of the wear pin and the disk, respectively. Thus, the pin exhibited a severe adhesive-dominated sliding wear. © 2012 Elsevier Ltd. All rights reserved.


Yan F.,Central South University | Yan F.,Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy | Gui W.,Central South University | Chen Y.,Central South University | And 2 more authors.
Chinese Control Conference, CCC | Year: 2012

In this paper, a kind of rough set knowledge reduction algorithm based on improving genetic algorithm is proposed by analyzing rough sets reduction. Support degree and importance degree of condition attribute on decision attribute in information system are as heuristic information in Genetic Algorithm. On the basic of that, the GA was improved by population and individual dissimilarity degree in order to enhanced system global optimization and accelerate the convergence rate. The Practical results show that the approach is time-saving and effective for solving knowledge reduction. © 2012 Chinese Assoc of Automati.


Yan F.,Central South University | Yan F.,Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy | Gui W.,Central South University | Chen Y.,Central South University | And 2 more authors.
Chinese Control Conference, CCC | Year: 2012

For the problem of adding cold charges operation in the PS Converter copper smelting, a kind of improving genetic algorithm is proposed. The GA was improved by population and individual dissimilarity degree and dissimilarity interval in order to enhanced global optimization and accelerate the convergence rate. The simulation results and production application demonstrate the effectiveness of the scheme which is beneficial to the operation optimization of PS Converter. © 2012 Chinese Assoc of Automati.


Yang Y.-L.,Central South University | Zhan L.-H.,Central South University | Li J.,Central South University | Li J.,Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2015

The constitutive modeling and springback simulation for AA2524 sheet in creep age forming (CAF) process were presented. A series of creep aging tests were performed on AA2524 at the temperature of 180-200 °C and under the stress of 140-210 MPa for 16 h. Based on these experimental data, material constitutive equations which can well characterize creep aging behaviors of the tested alloy were developed. The effect of interior stress distributed along the sheet thickness on springback was simulated using FE software MSC. MARC by compiling the established constitutive models into the user subroutine. The simulation results showed that the amount of sheet springback was 61.12% when merely considering tensile stress existing along the sheet thickness; while sheet springback was up to 65.93% when taking both tensile and compressive stresses into account. In addition, an AA2524 rectangular sheet was subjected to CAF experiment in resistance furnace. The springback value of the formed rectangular sheet was 68.2%, which was much closer to 65.93%. This confirms that both tensile and compressive stresses across the sheet thickness should be considered in accurately predicting springback of the sheet after forming, which can be more consistent with experimental results. © 2015 The Nonferrous Metals Society of China.


Li Y.,China University of Mining and Technology | Zhang Q.,Nanjing Southeast University | Lin Z.,China University of Mining and Technology | Wang X.,Changsha Engineering and Research Institute Ltd. of Nonferrous Metallurgy
International Journal of Mining Science and Technology | Year: 2016

A series of plane-strain physical model experiments are carried out to study the spatiotemporal evolution rule of rocks fracture surrounding gob-side roadway, which is subjected to the pressure induced by the mining process. The digital photogrammetry technology and large deformation analysis method are applied to measure the deformation and fracture of surrounding rocks. The experimental results indicate that the deformation and fracture of coal pillars are the cause to the instability and failure of the surrounding rocks. The spatiotemporal evolution rule of the rock deformation and fracture surrounding gob-side roadway is obtained. The coal pillar and the roof near coal pillar should be strengthened in support design. The engineering application results also can provide a useful guide that the combined support with wire meshes, beam, anchor bolt and cable is an effective method. © 2016.

Discover hidden collaborations