The application of active structural control technology to highway bridge structures subjected to high-impact loadings is investigated. The effects of high-impact loads on infrastructure, like heavy vehicle collisions with bridge piers, have not been studied as much as seismic load effects on structures. Due to this lack of research regarding impact loads and structural control, a focused study on the application of active control devices to infrastructure after impact events can provide valuable results and conclusions. This research applies active structural control to an idealized two-span, continuous girder, concrete highway bridge structure. The idealization of a highway bridge structure as a two degree-of-freedom structural system is used to investigate the effectiveness of control devices installed between the bridge pier and deck, the two degrees of freedom. The control devices are fixed to bracing between the bridge pier and girders and controlled by the proportional-integral-derivative (PID) control. The PID control gains are optimized by both the Ziegler–Nichols ultimate sensitivity method (USM) and a new method for this impact load application called particle swarm optimization (PSO). The controlled time-domain responses are compared to the uncontrolled responses, and the effectiveness of PID control, USM optimization, and PSO is compared for this control device configuration. The results of this investigation show PID control to be effective for minimizing both superstructure and substructure responses of highway bridges after high-impact loads. Deck response reductions of greater than 19% and 37% were seen for displacement and acceleration responses, respectively, regardless of the performance index used to analyze them. PSO was much more effective than USM optimization for tuning PID control gains.
The application of smart control technology to both aging and new infrastructure is essential to extending service life, increasing life safety, and decreasing repair and replacement costs. One area of control technology research for civil engineering structures that has received little attention historically is that of high-impact loads, such as collision events. The dissipation of impact energy using smart control devices, such as magnetorheological (MR) dampers, leads to less plastic deformation and damage, and a lower likelihood of collapse in civil engineering structures. Due to the short duration and high variability in magnitude of potential impact loads, the issue of sub-optimal controller performance arises. In order to boost controller performance and improve the effectiveness of the control system, a radar-based impact load identifier is proposed. This radar-based impact load identifier will be used to estimate impact loads from imminent impacting objects, for example vessels and trucks, thus providing input information to the control system before the impact actually occurs. This paper presents the characterization and validation, through laboratory tests, of one part of the radar-based impact load identifier, the range and velocity estimation of the incoming moving objects. The range and velocity information are then used to direct structural control based on laboratory impact tests. An ultrawideband monostatic pulsed radar is used for range and velocity measurements of a laboratory-scale impacting vehicle. The range and velocity measurements obtained from the radar scans are verified using physical measurements and control testing. The tests showed great accuracy for both range and velocity with less than 3% error for each measurement and demonstrated structural control based on these measurements. It is shown from control system testing that the proposed approach is effective in reducing the structural impact responses by 11-30%, depending on the performance index, for pre-impact structural stiffening with passive control of MR dampers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.