An experimental investigation was conducted on the flexural behavior of FRP-PVC confined concrete circular tubular members.A total of six specimens were prepared and tested under flexural loading.The main parameters v...An experimental investigation was conducted on the flexural behavior of FRP-PVC confined concrete circular tubular members.A total of six specimens were prepared and tested under flexural loading.The main parameters varied in the tests were the layer of FRP and the strengthening approach of BFRP and CFRP.The failure modes,ultimate bending capacity and stress-strain relation curves were investigated in details.Furthermore,the relation model of moment(M)-curvature(φ)was studied,and on the basis of M-φ relation model,a simplified formula was presented to compute the ultimate bending moment capacity.The results show that the external confinement of concrete specimens by FRP-PVC tubes results in enhancing the ultimate bending strength and ultimate deformation,and the ultimate bending capacity increased with the FRP layers.Simultaneously,the reinforcement effect in CFRP is better than that in BFRP.The ultimate bending moment capacity values predicted by the presented formula agree well with the experimental results,which imply that the presented formula is applicable and efficient for prediction of the ultimate bending moment capacity as well.展开更多
Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdu...Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdup increases with the increase in superficial gas velocity and the decrease in initial solid holdup in the dense zone of the fluidized bed.The average cross-sectional solid holdup decreases with increasing bed height and superficial gas velocity.The bed expansion coefficient increases with the increase in superficial gas velocity and the decrease in solid holdup.Correlations of average solid holdup,average cross-sectional solid holdup and bed expansion coefficient are also established and discussed.These correlations can provide guidelines for better understanding of the fluidization characteristics.展开更多
The bending rigidity of submerged vegetation is closely related with vegetative drag force. This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of sub...The bending rigidity of submerged vegetation is closely related with vegetative drag force. This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of submerged vegetation. Based on the dimensional analysis method, the factors influencing the bending rigidity of individual submerged vegetation were analyzed. The relationship between the relative bending rigidity and its influencing factors was investigated by experimental observation, and a relative bending rigidity expression for submerged vegetation was obtained by means of multiple linear regression method. The results show that the submerged vegetation has three states under different inflow conditions, and the each critical relative bending rigidity of individual submerged vegetation was determined for the different states of submerged vegetation.展开更多
文摘An experimental investigation was conducted on the flexural behavior of FRP-PVC confined concrete circular tubular members.A total of six specimens were prepared and tested under flexural loading.The main parameters varied in the tests were the layer of FRP and the strengthening approach of BFRP and CFRP.The failure modes,ultimate bending capacity and stress-strain relation curves were investigated in details.Furthermore,the relation model of moment(M)-curvature(φ)was studied,and on the basis of M-φ relation model,a simplified formula was presented to compute the ultimate bending moment capacity.The results show that the external confinement of concrete specimens by FRP-PVC tubes results in enhancing the ultimate bending strength and ultimate deformation,and the ultimate bending capacity increased with the FRP layers.Simultaneously,the reinforcement effect in CFRP is better than that in BFRP.The ultimate bending moment capacity values predicted by the presented formula agree well with the experimental results,which imply that the presented formula is applicable and efficient for prediction of the ultimate bending moment capacity as well.
文摘Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdup increases with the increase in superficial gas velocity and the decrease in initial solid holdup in the dense zone of the fluidized bed.The average cross-sectional solid holdup decreases with increasing bed height and superficial gas velocity.The bed expansion coefficient increases with the increase in superficial gas velocity and the decrease in solid holdup.Correlations of average solid holdup,average cross-sectional solid holdup and bed expansion coefficient are also established and discussed.These correlations can provide guidelines for better understanding of the fluidization characteristics.
基金supported by the Fundamental Research Funds for the Central Universities (Grant Nos. 2010B01514,2010B01314)the National Natural Science Foundation of China (Grant No. 51179057)
文摘The bending rigidity of submerged vegetation is closely related with vegetative drag force. This work aims at determining the effects of flow conditions and characteristics of vegetation on the bending rigidity of submerged vegetation. Based on the dimensional analysis method, the factors influencing the bending rigidity of individual submerged vegetation were analyzed. The relationship between the relative bending rigidity and its influencing factors was investigated by experimental observation, and a relative bending rigidity expression for submerged vegetation was obtained by means of multiple linear regression method. The results show that the submerged vegetation has three states under different inflow conditions, and the each critical relative bending rigidity of individual submerged vegetation was determined for the different states of submerged vegetation.
