摘要:

AbstractA study is carried out for investigating the effectiveness of active control systems for one‐storey torsionally coupled structures. The governing equations of motion of the system are derived. The control forces are obtained using the classical linear optimal control algorithm. The stochastic seismic response of a torsionally coupled controlled system is investigated under important parametric variations such as: uncoupled lateral time period, system eccentricity and ratio of uncoupled torsional to lateral frequency of the system. In order to investigate the effectiveness of the control device, the response of the system with control device is compared with the corresponding system without control device. Further, the controlled response of the torsionally coupled system is compared with the corresponding response of the uncoupled system. It is shown that the control mechanism is also equally effective in reducing the seismic response of a torsionally coupled system. In addition, it is to be noted that the effectiveness of the active control device is overestimated when it is designed without considering the effects of torsional couplin

ISSN:1122-8385    

DOI:10.1002/stc.4300080101

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

摘要:

AbstractA producer of base isolation devices made available low damping elastomeric bearings in a size consistent with the shaking table facilities available at the Department of Structural Mechanics of the University of Pavia in Italy. The mass the shaking table can bear is 400 kg. This means that one base isolator is enough as vertical support, but more isolators would provide an excessive horizontal stiffness. Two further supports were realised by a steel‐teflon contact. It showed good sliding capability under a mass of 100 kg, while for the mass of 400 kg a significant friction effect was emphasised. The laboratory tests were able to identify the device behaviour by collecting absolute inertial force/relative displacement couples. The constitutive law is inferred by a genetic algorithm. This aspect is deeply investigate

ISSN:1122-8385    

DOI:10.1002/stc.4300080102

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

ISSN:1122-8385    

DOI:10.1002/stc.4300080103

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

摘要:

AbstractThis article is an extended summary of a Ph.D. Thesis, see (Hansen, 1998). In the thesis theoretical and experimental effects of flap control on a bridge section are compared. Dynamics of long suspension bridges is summarized with special attention on the flutter phenomenom. The aerodynamic derivatives for a flat plate with flaps are derived based on the Theodorsen theory. Estimation of the flutter wind velocity is shown when both the Theodorsen method and the Air Material Command method are used. Three control algorithms are described, namely Classical Linear Optimal closed‐loop control, Instantaneous Optimal closed‐loop control and control with constant phase angles between the motion of the bridge section and the flap motions. Wind tunnel experiments are described and the experimental data are analysed. Finally the results of the wind tunnel experiments are compared to the the

ISSN:1122-8385    

DOI:10.1002/stc.4300080104

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

摘要:

AbstractThis paper is an extended abstract of the thesis of J.‐S. Briffaut. It treats the active control of flexible structures. In the first part the design of open‐loop control laws for beams is considered. In the second the implementation of Komornik's full state feed‐back law. In the third and fourth numerical results for the control of frames made of beams under bending and traction‐comp

ISSN:1122-8385    

DOI:10.1002/stc.4300080105

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

ISSN:1122-8385    

DOI:10.1002/stc.4300080106

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

ISSN:1122-8385    

DOI:10.1002/stc.4300080107

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY

ISSN:1122-8385    

DOI:10.1002/stc.4300080108

出版商:John Wiley&Sons, Ltd    

年代:2001

数据来源: WILEY