http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Numerical simulation of columns with un-bonded reinforcing bars for crack control
G. Chen,H. Fukuyama,M. Teshigawara,H. Etoh,K. Kusunoki,H. Suwada 국제구조공학회 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.4
Following previous work carried out in Building Research Institute in Japan, finite element analyses of conceptual column designs are performed in this paper. The effectiveness of the numerical model is evaluated by experimental tests and parametric studies are conducted to determine influential factors in conceptual column designs. First, three different column designs are analysed: bonded, unbonded, and un-bonded with additional reinforcing bars. The load-displacement curves and cracking patterns in concrete are obtained and compared with experimental ones. The comparisons indicate that the finite element model is able to reflect the experimental results closely. Both numerical and experimental results show that, the introduction of un-bonded zones in a column end can reduce cracking strains, accordingly reduce the stiffness and strength as well; the addition of extra reinforcement in the un-bonded zones can offset the losses of the stiffness and strength. To decide the proper length of the un-bonded zones and the sufficient amount of the additional reinforcing bars, parametric studies are carried out on their influences. It has been found that the stiffness of un-bonded designs slightly decreases with increasing the length of the un-bonded zones and increases with the size of the additional reinforcing bars.
Numerical simulation of columns with un-bonded reinforcing bars for crack control
Chen, G.,Fukuyama, H.,Teshigawara, M.,Etoh, H.,Kusunoki, K.,Suwada, H. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.4
Following previous work carried out in Building Research Institute in Japan, finite element analyses of conceptual column designs are performed in this paper. The effectiveness of the numerical model is evaluated by experimental tests and parametric studies are conducted to determine influential factors in conceptual column designs. First, three different column designs are analysed: bonded, un-bonded, and un-bonded with additional reinforcing bars. The load-displacement curves and cracking patterns in concrete are obtained and compared with experimental ones. The comparisons indicate that the finite element model is able to reflect the experimental results closely. Both numerical and experimental results show that, the introduction of un-bonded zones in a column end can reduce cracking strains, accordingly reduce the stiffness and strength as well; the addition of extra reinforcement in the un-bonded zones can offset the losses of the stiffness and strength. To decide the proper length of the un-bonded zones and the sufficient amount of the additional reinforcing bars, parametric studies are carried out on their influences. It has been found that the stiffness of un-bonded designs slightly decreases with increasing the length of the un-bonded zones and increases with the size of the additional reinforcing bars.
Yuusuke YAMAGUCHI,A. Fukuyama,H. Nakajima,H. Higaki,K. Nakagome,K. Nemoto,M. Katano,M. Ichimura,S. Kakimoto,T. Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III
A wide-band radio-frequency (RF) probe system was newly constructed for the active diagnostic of the eigenmode formations in the ion-cyclotron range of frequencies in the GAMMA 10 tandem mirror. A bar-type antenna was installed in the peripheral region in the minimum-B anchor cell. A low-power RF pulse with the frequency sweep from 8 to 20 MHz is applied to the antenna. The waves excited in the plasma are detected with a magnetic probe. The excitation of eigenmodes is described by using the antenna-plasma-probe transfer function. The transfer function can be obtained from the antenna current signal and the magnetic probe signal. When the real and the imaginary part of the transfer function are plotted in the complex plane, the resultant curves are approximately circles, indicating an eigenmode formation. It is found that the several fast wave eigenmodes can be excited in the present experimental condition.