期刊：
Materials and Design,2011年32(4):2149-2156 ISSN：0261-3069
通讯作者：
Xiao, Yan-Ping
作者机构：
[Pan, Qing-Lin; Li, Wen-Bin; He, Yun-Bin; Xiao, Yan-Ping; Liu, Xiao-Yan] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Pan, Qing-Lin] Minist Educ, Key Lab Nonferrous Mat Sci & Engn, Changsha 410083, Peoples R China.;[Li, Wen-Bin] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Xiao, Yan-Ping] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
关键词：
A. Non-ferrous metals and alloys;E. Corrosion;F. Microstructure
摘要：
Influence of retrogression and re-aging treatment on the microstructure, strength, exfoliation corrosion, inter-granular corrosion and stress corrosion cracking of an Al-Zn-Mg-Cu alloy has been investigated by means of optical microscope (OM), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS). The results show that retrogression and re-aging treatment can increase the size and the distribution discontinuity of the grain boundary precipitates, and lead to the increase of the corrosion resistance without the loss of strength and ductility. In addition, the analysis of electrochemical impedance spectroscopy shows that retrogression and re-aging treatment can enhance the resistance to exfoliation corrosion. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.
作者：
Li Wenbin;Pan Qinglin;Xiao Yanping;He Yunbin;Liu Xiaoyan
期刊：
Transactions of Nonferrous Metals Society of China,2011年21(10):2127-2133 ISSN：1003-6326
通讯作者：
Pan Qing-lin
作者机构：
[Pan Qinglin; Li Wenbin; Xiao Yanping; Liu Xiaoyan; He Yunbin] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Li Wenbin] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Pan Qing-lin] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
摘要：
The microstructural evolution and composition distribution of an Al-Zn-Cu-Mg-Sc-Zr alloy during homogenization were investigated by optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectrometry(EDS),X-ray diffraction(XRD) and differential scanning calorimetry(DSC).The results show that severe dendritic segregation exists in Al-Zn-Cu-Mg-Sc-Zr alloy ingot.There are a lot of eutectic phases at grain boundary and the distribution of the main elements varies periodically along interdendritic region.The main eutectic phases at grain boundary are Al7Cu2Fe phase and T(Al2Mg3Zn3).The residual phases are dissolved into the matrix gradually during homogenization with increasing temperature and prolonging holding time,which can be described by a constitutive equation in exponential function.The overburnt temperature of the alloy is 473.9 ℃.The optimum parameters of homogenization are 470 ℃ and 24 h,which is consistent with the result of homogenization kinetic analysis.
作者机构：
[Yi Weijian; Feng Haoxiong] Hunan Univ, Sch Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Feng Haoxiong] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
会议名称：
2nd International Workshop on Renewable Energy and Development (IWRED)
会议时间：
APR 20-22, 2018
会议地点：
Guilin, PEOPLES R CHINA
会议主办单位：
[Feng Haoxiong;Yi Weijian] Hunan Univ, Sch Civil Engn, Changsha 410082, Hunan, Peoples R China.^[Feng Haoxiong] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
会议论文集名称：
IOP Conference Series-Earth and Environmental Science
摘要：
The MCFT on shear theoretical calculation method in reinforced concrete beams is expressed by the mathematical relationship based on the theory of MCFT, and the theoretical calculation formula is simplified. Finally the results with shear theoretical calculation method of simplified MCFT can be well fit with the test datas. That shows the simplified theoretical calculation method of shear is reasonable, thus another simple method for shear calculation of the reinforced concrete T beams is provided.
摘要：
The mechanical performance of recycled aggregate concrete (RAC) is investigated. An experiment on the complete stress-strain curve under uniaxial compression loading of RAC is carried out. The experimental results indicate that the peak stress, peak strain, secant modulus of the peak point and original point increase with the strength grade of RAC enhanced. On the contrary, the residual stress of RAC decreases with the strength grade enhancing, and the failure of RAC is often broken at the interface between the recycled aggregate and the mortar matrix. Finally, the constitutive model of stress-strain model of RAC has been constituted, and the results from the constitutive model of stress-strain meet the experiment results very well.
摘要：
The response surface method (RSM) is one of the main approaches for analyzing reliability problems with implicit performance functions. An improved adaptive RSM based on uniform design (UD) and double weighted regression (DWR) was presented. In the proposed method, the basic principle of the iteratively adaptive response surface method is applied. Uniform design is used to sample the fitting points. And a double weighted regression system considering the distances from the fitting points to the limit state surface and to the estimated design points is set to determine the coefficients of the response surface model. Compared with the conventional approaches, the fitting points selected by UD are more representative, and a better approximation in the key region is also observed with DWR. Numerical examples show that the proposed method has good convergent capability and computational accuracy.
摘要：
In order to present basic guidance for system calibration of split Hopkinson pressure bar (SHPB) with the special shape striker, wave characteristics and dynamic responses of SHPB under striker impact were analyzed. Stress generated by the special shape striker tends to have a half-sine waveform and has little wave dispersion during its propagation. Impact velocities of the special shape striker and peak values of generated stress still have linear relation but with a different coefficient from that of cylindrical strikers. From stress histories on the surfaces of the input bar impacted by the special shape striker off-axially and obliquely, it is found that the misalignment impacts usually trigger wave distortion and amplitude decrease, which can be used to identify the poor system adjustment. Finally, the system calibration of SHPB with the special shape striker can be classified into four steps: system adjustment, wave distortion identification, measurement calibration and transmission calibration, where the measurement calibration factor and transmission calibration factor are elaborated and redefined.
作者：
Wenbin Li;Qinglin Pan;Liang Zou;Wenjie Liang;Yunbin He;Junsheng Liu
期刊：
Rare Metals,2009年28(1):102-106 ISSN：1001-0521
通讯作者：
Li Wenbin
作者机构：
[Pan Qinglin; Li Wenbin; Liang Wenjie; Zou Liang; He Yunbin; Liu Junsheng] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Li Wenbin] Hunan City Univ, Dept Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Li Wenbin] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
摘要：
Five kinds of Al-Zn-Mg-Cu-Zr based alloys with different Sc additions were prepared by ingot metallurgy. The effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys were investigated using tensile tests, optical microscopy (OM), and transmission electron microscopy (TEM). The results show that the ultimate tensile strength and yield strength are improved by 94 and 110 MPa, respectively, and the elongation to failure remains at a reasonable extent (11.1%) in the Al-Zn-Mg-Cu-Zr based alloy with 0.21 wt.% Sc addition after solution heat treatment at 475℃ for 40 min and then aged at 120℃ for 24 h. The addition of minor Sc induces the formation of Al_3(Sc,Zr) particles, which are highly effective in refining the cast microstructures, retarding recrystallization, and pinning dislocations. The increment of strength is attributed mainly to fine grain strengthening, precipitation strengthening of Al_3(Sc,Zr) particles, and substructure strengthening.
摘要：
Corrosion behaviour of different tempers (namely NA, UA, PA and OA) of AlZnMgCuZrSc alloy was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), optical microscopy (OM) and transmission electron microscopy (TEM). Over aged (OA) can decrease the susceptibility to exfoliation due to the discontinuous distribution of the η precipitates at the grain boundaries, cause a negative shift of the corrosion potential (Ecorr), and lead to the prolonging of the time of the appearance of two time constants in impedance diagrams. In addition, AlZnMgCuZrSc alloy with over aged treatment has an enhanced resistance to exfoliation corrosion.
作者：
Fa-xing, Ding;Jing, Liu;Xue-mei, Liu;Zhi-wu, Yu;Yong-suo, Li
期刊：
Journal of Constructional Steel Research,2018年144:153-165 ISSN：0143-974X
通讯作者：
Liu Jing
作者机构：
[Jing, Liu; Fa-xing, Ding; Zhi-wu, Yu] Cent S Univ, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.;[Jing, Liu; Yong-suo, Li] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Xue-mei, Liu] Queensland Univ Technol, Sch Civil Engn & Built Environm, Brisbane, Qld 4000, Australia.
通讯机构：
[Liu Jing] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Steel-concrete composite beams;Quasi static test;Hysteretic performance;Degree of shear connection
摘要：
This study aimed to investigate the seismic behavior of simply supported steel-concrete composite I beam and box beam through a quasi-static experimental study. A total of 22 composite beams included in the experiments, and parameters including shear connection degree, transverse reinforcement ratio, longitudinal reinforcement ratio, section type, diameter of stud, and web thickness were investigated. Based on the test, hysteretic response, skeleton curves, failure mode, stiffness degradation, ductility, and energy dissipation were discussed. Results show the following: (1) Composite beams have favorable seismic performance, the displacement ductility ratio ranged from 2.5 to 8.75, whereas the maximum equivalent viscous damping ratio ranged from 0.219 to 0.470. (2) The higher the degree of shear connection, longitudinal reinforcement, and transverse reinforcement, the plumper the hysteretic curve and the greater the bearing and energy dissipation capacity. The ductility of composite beam increased as the longitudinal reinforcement ratio increased. The stiffness degradation and residual deformation were less effected by other parameters. (3) Findings suggest that the transverse reinforcement ratio ranged from 0.4% to 0.8%, the positive shear connection degree should be greater than 1, and the spacing of stud in the negative moment region should not be larger than that in the positive moment region. To ensure welding quality and convenient construction, a large diameter of stud should be applied in practical engineering. Moreover, when the girder is welded by a thin web, transverse diaphragm plate and vertical reinforced rib should be added in the steel girder if these areas are heavily loaded. (C) 2018 Elsevier Ltd. All rights reserved.
期刊：
Journal of Central South University of Technology,2011年18(2):279-284 ISSN：1005-9784
通讯作者：
Pan Qing-lin
作者机构：
[Pan, Qing-Lin; Li, Wen-Bin; Xiao, Yan-Ping; Liu, Xiao-Yan; He, Yun-Bin] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Li, Wen-Bin] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Pan Qing-lin] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Al-Zn-Cu-Mg-Sc-Zr alloy;retrogression and re-aging treatment;microstructure;mechanical properties;stress corrosion cracking
摘要：
The mechanical properties and stress corrosion cracking (SCC) resistance of an Al-Zn-Cu-Mg-Sc-Zr alloy under different aging conditions were investigated. The dependence of microstructure and mechanical properties on aging parameters was evaluated by tensile test, hardness test and conductivity measurement. The results show that for the alloys with retrogression and re-aging treatment (RRA), the conductivity increases with the retrogression time and temperature, while the tensile strength decreases. The transmission electron microscopy (TEM) results show that the precipitates η(MgZn2) at grain boundary aggregate apparently with retrogression time and the precipitates inside the matrix exhibit the similar distribution to T6 temper, which comprises fine GP zones, large η′(MgZn2) and η(MgZn2) phases. According to the mechanical properties and microstructure observations, the optimal RRA regime is recommended to be 120 °C, 24 h + 180 °C, 30 min + 120 °C, 24 h. The strength level of the alloy after the optimum RRA treatment is similar to that in T6 condition and the SCC resistance is improved obviously in contrast to T6 condition.
作者：
Liu Xi-ling*;Li Xi-bing;Hong Liang;Yin Tu-bing;Rao Meng
期刊：
Journal of Central South University,2015年22(9):3571-3577 ISSN：2095-2899
通讯作者：
Liu Xi-ling
作者机构：
[Yin Tu-bing; Liu Xi-ling; Li Xi-bing; Rao Meng] Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Peoples R China.;[Liu Xi-ling] Univ British Columbia, Norman B Keevil Inst Min Engn, Vancouver, BC V6T 1Z4, Canada.;[Hong Liang] Hunan City Univ, Sch Civil Engn, Yiyang 413049, Peoples R China.
通讯机构：
[Liu Xi-ling] Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Peoples R China.
摘要：
Acoustic emission tests were performed using a split Hopkinson pressure bar system (SHPB) on 50-mm-diameter bars of granite, limestone, sandstone and skarn. The results show that the amplitude distribution of hits is not well centralized around 50 dB, and that some hits with large amplitudes, usually larger than 70 dB, occur in the early stages of each test, which is different from the findings from static and low-loading-rate tests. Furthermore, the dominant frequency range of the recorded acoustic emission waveforms is between 300 kHz and 500 kHz, and frequency components higher than 500 kHz are not significant. The hit with the largest values of amplitude, counts, signal strength, and absolute energy in each test, displays a waveform with similar frequency characteristics and greater correlation with the waveform obtained from the elastic input bar of the split Hopkinson pressure bar system compared with the waveforms of the other hits. This indicates that the hit with the largest values of amplitude, counts, signal strength, and absolute energy is generated by elastic wave propagation instead of fracture within the rock specimen.
摘要：
The exfoliation corrosion behavior of an Al–Zn–Mg–Cu–Zr alloy containing Sc artificially aged at 120 °C for 24 h is studied by macroscopic observation techniques and electrochemical impedance spectroscopy (EIS) measurements. After 48 h immersion, the blisters start bursting and delamination initiates, along with the appearance of two time constants in the impedance diagrams. According to the simulation by equivalent circuit, the corrosion rate decreases sharply and then reaches a steady state, which is due to the change of the solution pH and oxide layer thickness, as well as the accumulation of corrosion products.
摘要：
The classical theory of heat conduction (Fourier theory) predicts an infinite speed for thermal disturbance propagation, which is physically unrealistic. By extending the classical Fourier heat conduction and Fick's diffusion, this paper presents a hyperbolic diffusion law with different phase lags of thermal and moisture fluxes to simulate coupled heat-moisture diffusion-propagation behavior. Transient hygrothermal and elastic response of an infinitely long cylinder subjected to sudden hygrothermal loadings at the surface is studied. By using Laplace transform and decoupling technique, a closed form solution of temperature, moisture, displacements and stresses is determined. The analytical results show that the thermal and moisture relaxation times or phase lags of heat and moisture fluxes play a significant role in the early stage of transient response after heat/moisture shock. The classical results corresponding to vanishing phase lags can be recovered from the present ones. For non-vanishing phase lags, hygrothermal waves have finite propagation speeds. Numerical results are calculated and displayed graphically to show the influence of the phase lags of heat and moisture fluxes on transient hygrothermoelastic fields. A comparison between classic model and hyperbolic hygrothermal coupling model is given. Based on the non Fourier heat conduction and non-Fick diffusion, some shortcomings induced by the classical Fourier's and Fick's laws can be effectively avoided. (C) 2018 Elsevier Ltd. All rights reserved.
作者机构：
[Qiu, Zhenfeng; Cao, Ting; Wang, Junjie] Chongqing Jiaotong Univ, Key Lab Hydraul & Waterway Engn, Minist Educ, Chongqing 400074, Peoples R China.;[Qiu, Zhenfeng; Wang, Junjie] Chongqing Jiaotong Univ, Natl Engn Res Ctr Inland Waterway Regulat, Chongqing 400074, Peoples R China.;[Cao, Ting; Li, Yongsuo] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Chen, Yulong] Tsinghua Univ, State Key Lab Hydrosci & Engn, Beijing 100084, Peoples R China.
通讯机构：
[Qiu, ZF; Cao, T; Wang, JJ] Chongqing Jiaotong Univ, Key Lab Hydraul & Waterway Engn, Minist Educ, Chongqing 400074, Peoples R China.;[Qiu, ZF; Wang, JJ] Chongqing Jiaotong Univ, Natl Engn Res Ctr Inland Waterway Regulat, Chongqing 400074, Peoples R China.;[Cao, T; Li, YS] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Chen, Yulong] Tsinghua Univ, State Key Lab Hydrosci & Engn, Beijing 100084, Peoples R China.
关键词：
sandstone and mudstone particles;rheological deformation;segmented rheological model;rheological limit strain;rheological test
摘要：
A mixture of sandstone and mudstone particles is often used as the main filling material for many agriculture-related and civil engineering projects, including rock-fill dams and foundations. The long-term rheological deformation experienced by rock-fill dams and foundations filled with this mixture is much bigger than that of coarse-grained and cohesive soils, due to the deterioration and softening of the mudstone particles. This study focuses on the rheological deformation of a sandstone-mudstone particle mixture, prepared by mixing sandstone and mudstone particles, based on the content by weight of four mudstone particle types. Confined uniaxial compression tests were performed to test the rheological deformation of 24 samples of the mixture, and a stress-strain curve was obtained for each test. On the basis of compression curves, the rheological process of the mixture was divided into four phases: linear, attenuation rheological, secondary attenuation rheological and stable phases. The three defining features of the curve, namely the rheological attenuation factors, attenuation rheology critical strain and limited rheological strain, were then determined and modeled. A segmented rheological model was then proposed, based on a modified attenuation rheological constitutive model for coarse-grained soil. The modelled results compared well with the experimental data, and the modelled compression-curve prediction was able to describe the two-stage attenuation rheology features (attenuation rheological and secondary attenuation rheological phases) of the sandstone-mudstone particle mixture.
摘要：
Cast-in-place concrete large-diameter pipe pile (referred to as PCC pile) is widely used for pile-supported embankment over soft soils in China. However, the studies focused on the sliding stability and calculated method of this new pile type under lateral load was relatively little. Therefore, base on PCC pile-supported embankments in the eastern coastal region of China case study, undrained shear strength, conventional p-y criteria, and modified pile modulus are recommended for lateral bearing capacity calculation basing on LPILE plus 5.0. The correctness of calculated method is verified by comparing the results on lateral load versus pile top deflection with those obtained by field test. The performances of drilled shaft with the same out-diameter, and PCC pile without considering pile core soils are also carried out for comparative analysis. The result shows that the performances of PCC piles under lateral load can be calculated through LPILE software with conventional p-y criteria of drilled shaft, and modified modulus of piles. The result also shows that when comparing with conventional drilled shaft with the same out-diameter, the lateral bearing capacity of PCC pile is reduced nearly about 20 %, while with nearly about 60 % concrete usage are saved. The results of this paper can provide design and calculation guide for practical PCC pile used for landslide disaster treatment under lateral load in United States.
