A dynamic triaxial instrument was used to study the effects of different concentrations of sodium chloride and stress amplitudes on the dynamic properties of an expansive soil under cyclic loading.In particular,four p...A dynamic triaxial instrument was used to study the effects of different concentrations of sodium chloride and stress amplitudes on the dynamic properties of an expansive soil under cyclic loading.In particular,four parameters were considered in such a parametric investigation,namely,hysteresis curve morphology characteristic non-closure degreeεp,the ratio of the short and long axisα,the slope of the long axis k and the enclosed area S.The results show that with an increase in the sodium chloride concentration,the soil particle double electric layer becomes thinner,the distance between soil particles decreases,and the whole sample becomes denser.Theεp-N,α-N and S–N relation curves all show a decreasing trend.The ratio of plastic deformation to total deformation grows with increasing the dynamic stress amplitude,and the curves show an upwards trend.The k-N relationship curve displays an increasing trend with the concentration and a general downwards trend as the dynamic stress amplitude is made higher.This also indicates that sodium chloride solutions can improve the engineering properties of expansive soil to a certain extent.With an increase in the vibration times N,the shape of the hysteretic curve becomes narrower,and the whole soil exhibits a cyclic strain hardening.With the help of an exponential function,a model is introduced to predict the relationship between the concentration and the hysteretic curve.展开更多
This paper describes the quasi-static testing and analytical modelling of the hysteretic behavior of aluminum alloy rigid bus-flexible connectors of 220 kV electrical substations.The main objective of the study is to ...This paper describes the quasi-static testing and analytical modelling of the hysteretic behavior of aluminum alloy rigid bus-flexible connectors of 220 kV electrical substations.The main objective of the study is to experimentally investigate the hysteretic behavior of six different types of rigid bus-flexible connectors 220 kV electrical substations when subjected to cyclic loading.Another objective is to theoretically study the flexibility and effectiveness of a previously proposed analytical model in fitting the experimental hysteresis loops of the tested rigid bus-flexible connectors.The experimental investigation indicates that the tested rigid bus-flexible connectors exhibit highly asymmetric hysteresis behavior along with tension stiffening effect.The theoretical study demonstrates that the generalized Bouc-Wen model has high flexibility and is effective in fitting the experimental hysteresis resisting force-displacement curves of the six tested rigid bus-flexible connectors.展开更多
The influence of the hysteretic behaviour in reactive sputtering with a pure aluminium target in the presence of argon and oxygen plasma on transmittance and surface free energy of aluminium oxide films was investigat...The influence of the hysteretic behaviour in reactive sputtering with a pure aluminium target in the presence of argon and oxygen plasma on transmittance and surface free energy of aluminium oxide films was investigated by plasma optical emission spectroscopy technology. The evolutions of aluminium, and aluminium oxide emission lines as functions of oxygen flow rate at constant power and pressure were studied. A steep transition from the metallic sputtering to the compound sputtering was observed upon increasing the oxygen flow rate from 0.0 SCCM to above 2.0 SCCM. Then an optimal deposition zone was obtained through analyzing the hysteretic curves of aluminium and aluminium oxide emission lines. The evolution of crystal structures of samples was discerned by X-ray diffraction spectra data. Energy dispersive X-ray spectroscopy data also demonstrate the relationship between the chemical compositions of aluminium oxide films and the hysteretic behaviour. The film deposited between 1.5 SCCM and 2.0 SCCM oxygen flow rate displays an optimal and stoichiometic atomic ratio of O to Al and mass ratio of O to Al. The changes in the transmittance of samples were discovered to depend on the oxygen flow rate by UV-VIS transmittance spectra, and the changes in surface free energy were studied by contact angle measurement.展开更多
文摘A dynamic triaxial instrument was used to study the effects of different concentrations of sodium chloride and stress amplitudes on the dynamic properties of an expansive soil under cyclic loading.In particular,four parameters were considered in such a parametric investigation,namely,hysteresis curve morphology characteristic non-closure degreeεp,the ratio of the short and long axisα,the slope of the long axis k and the enclosed area S.The results show that with an increase in the sodium chloride concentration,the soil particle double electric layer becomes thinner,the distance between soil particles decreases,and the whole sample becomes denser.Theεp-N,α-N and S–N relation curves all show a decreasing trend.The ratio of plastic deformation to total deformation grows with increasing the dynamic stress amplitude,and the curves show an upwards trend.The k-N relationship curve displays an increasing trend with the concentration and a general downwards trend as the dynamic stress amplitude is made higher.This also indicates that sodium chloride solutions can improve the engineering properties of expansive soil to a certain extent.With an increase in the vibration times N,the shape of the hysteretic curve becomes narrower,and the whole soil exhibits a cyclic strain hardening.With the help of an exponential function,a model is introduced to predict the relationship between the concentration and the hysteretic curve.
基金National Natural Science Foundation of China under Grant No.51978397。
文摘This paper describes the quasi-static testing and analytical modelling of the hysteretic behavior of aluminum alloy rigid bus-flexible connectors of 220 kV electrical substations.The main objective of the study is to experimentally investigate the hysteretic behavior of six different types of rigid bus-flexible connectors 220 kV electrical substations when subjected to cyclic loading.Another objective is to theoretically study the flexibility and effectiveness of a previously proposed analytical model in fitting the experimental hysteresis loops of the tested rigid bus-flexible connectors.The experimental investigation indicates that the tested rigid bus-flexible connectors exhibit highly asymmetric hysteresis behavior along with tension stiffening effect.The theoretical study demonstrates that the generalized Bouc-Wen model has high flexibility and is effective in fitting the experimental hysteresis resisting force-displacement curves of the six tested rigid bus-flexible connectors.
基金supported by the Fundamental Research Funds for the Central Universities of China(N110403011)Science and Technology Plan of Shenyang City(F12-028-200),China
文摘The influence of the hysteretic behaviour in reactive sputtering with a pure aluminium target in the presence of argon and oxygen plasma on transmittance and surface free energy of aluminium oxide films was investigated by plasma optical emission spectroscopy technology. The evolutions of aluminium, and aluminium oxide emission lines as functions of oxygen flow rate at constant power and pressure were studied. A steep transition from the metallic sputtering to the compound sputtering was observed upon increasing the oxygen flow rate from 0.0 SCCM to above 2.0 SCCM. Then an optimal deposition zone was obtained through analyzing the hysteretic curves of aluminium and aluminium oxide emission lines. The evolution of crystal structures of samples was discerned by X-ray diffraction spectra data. Energy dispersive X-ray spectroscopy data also demonstrate the relationship between the chemical compositions of aluminium oxide films and the hysteretic behaviour. The film deposited between 1.5 SCCM and 2.0 SCCM oxygen flow rate displays an optimal and stoichiometic atomic ratio of O to Al and mass ratio of O to Al. The changes in the transmittance of samples were discovered to depend on the oxygen flow rate by UV-VIS transmittance spectra, and the changes in surface free energy were studied by contact angle measurement.
