Preface to ?Practical applications of active and semi-active structural control systems to actual civil engineering structures?

2001 ◽  
Vol 30 (11) ◽  
pp. 1563-1563 ◽  
Author(s):  
Takuji Kobori
2020 ◽  
Vol 10 (8) ◽  
pp. 2786 ◽  
Author(s):  
Hoofar Shokravi ◽  
Hooman Shokravi ◽  
Norhisham Bakhary ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů

Structural health monitoring (SHM) is the main contributor of the future’s smart city to deal with the need for safety, lower maintenance costs, and reliable condition assessment of structures. Among the algorithms used for SHM to identify the system parameters of structures, subspace system identification (SSI) is a reliable method in the time-domain that takes advantages of using extended observability matrices. Considerable numbers of studies have specifically concentrated on practical applications of SSI in recent years. To the best of author’s knowledge, no study has been undertaken to review and investigate the application of SSI in the monitoring of civil engineering structures. This paper aims to review studies that have used the SSI algorithm for the damage identification and modal analysis of structures. The fundamental focus is on data-driven and covariance-driven SSI algorithms. In this review, we consider the subspace algorithm to resolve the problem of a real-world application for SHM. With regard to performance, a comparison between SSI and other methods is provided in order to investigate its advantages and disadvantages. The applied methods of SHM in civil engineering structures are categorized into three classes, from simple one-dimensional (1D) to very complex structures, and the detectability of the SSI for different damage scenarios are reported. Finally, the available software incorporating SSI as their system identification technique are investigated.


Author(s):  
Richard E. Klein

This paper reflects back on the author’s research in structural control, originating in the early 1970’s. Upon reflection, in the early 1970’s and even as far as into the 1990’s, it constituted near heresy to suggest that large civil engineering structures could be candidates for control. The previous techniques of the 1930’s of building structures with masonry and stone were then being phased out, being replaced with lighter and more cost-effective steel-framed structures. The newer designs then emerging in the late 1960’s and early 1970’s were steel-framed structures that functioned as cantilevered tubes. The characteristic designs emerging included an absence of stone or masonry especially around the steel pillars, glass or similar non-load bearing cladding. Additionally, interior walls were non-load bearing affording more spacious rooms as well as affording the occupants the ability to reposition interior walls as desired. Moreover, the newly emerging steel-framed structures with increased compliance properties were increasingly prone to wind excitations as compared to the prior generation of structures. As a consequence, a number of these newer structures exhibited increased sway and other related dynamic behaviors. My mechanical engineering servomechanisms background included groundings in observability, controllability, as well as control of spatially distributed systems. Therefore, I felt confident then that control systems theoretic methods held promise to produce favorable and cost-effective results if properly applied to problematic civil engineering structures. That confidence still remains. I also realized the critical importance of being able to design structures in advance to be controlled, as opposed to the less desirable situation of dealing with an after-the-fact retrofit of an existing problematic structure. This paper affords an opportunity for the author to provide his anecdotal recollections and afterthoughts. Because the story to be told is of personal recollections, it is presented in first person.


1983 ◽  
Vol 73 (4) ◽  
pp. 1139-1159
Author(s):  
P. N. Agrawal

abstract An earthquake of MS = 6.3 occurred on 20 January 1982 near the east coast of Great Nicobar Island (in the Bay of Bengal), India and caused great panic among the inhabitants. Ground Fissures and damage to civil engineering structures was also caused. A study comprised of the recording of aftershocks and their migration, the preparation of an isoseismal map, and the compilation of other damage data is presented. Some recommendations have been made to permit suitable safeguards in future development.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
V. H. Nguyen ◽  
J. Mahowald ◽  
S. Maas ◽  
J.-C. Golinval

The aim of this paper is to apply both time- and frequency-domain-based approaches on real-life civil engineering structures and to assess their capability for damage detection. The methodology is based on Principal Component Analysis of the Hankel matrix built from output-only measurements and of Frequency Response Functions. Damage detection is performed using the concept of subspace angles between a current (possibly damaged state) and a reference (undamaged) state. The first structure is the Champangshiehl Bridge located in Luxembourg. Several damage levels were intentionally created by cutting a growing number of prestressed tendons and vibration data were acquired by the University of Luxembourg for each damaged state. The second example consists in reinforced and prestressed concrete panels. Successive damages were introduced in the panels by loading heavy weights and by cutting steel wires. The illustrations show different consequences in damage identification by the considered techniques.


2001 ◽  
Vol 2 (2) ◽  
pp. 63-71 ◽  
Author(s):  
Wim Moerman ◽  
Luc Taerwe ◽  
Wim De Waele ◽  
Joris Degrieck ◽  
Roel Baets

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