Large-scale shaking table test of steel braced frame with controlled rocking and energy dissipating fuses (original) (raw)
Related papers
Structures Congress 2010, 2010
This is the second of two companion papers that investigate the design and behavior of steel braced frames that resist earthquake effects through controlled rocking. By employing vertical post-tensioning and energy dissipating fuses, the controlled rocking systems can sustain large earthquake ground motions with minimal damage and without residual drift. This paper describes a series of large (two-thirds) scale dynamic shaking table tests, conducted at the E-Defense facility in Japan, to validate the system behavior for ground motions with intensities up to and beyond those of the maximum considered earthquake (MCE) level. The tests investigate response with alternative fuse designs and variable post-tensioning. Results of nonlinear dynamic analyses are shown to compare well with the shake table tests, which can be extended to assess the collapse performance of the controlled rocking frames, using procedures outlined in the FEMA P695 methodology to evaluate provisions for seismic design.
Structures Congress 2010, 2010
This is the second of two companion papers that investigate the design and behavior of steel braced frames that resist earthquake effects through controlled rocking. By employing vertical post-tensioning and energy dissipating fuses, the controlled rocking systems can sustain large earthquake ground motions with minimal damage and without residual drift. This paper describes a series of large (two-thirds) scale dynamic shaking table tests, conducted at the E-Defense facility in Japan, to validate the system behavior for ground motions with intensities up to and beyond those of the maximum considered earthquake (MCE) level. The tests investigate response with alternative fuse designs and variable post-tensioning. Results of nonlinear dynamic analyses are shown to compare well with the shake table tests, which can be extended to assess the collapse performance of the controlled rocking frames, using procedures outlined in the FEMA P695 methodology to evaluate provisions for seismic design.
IRJET, 2022
Seismic energy dissipation consists of many methods like dampers, viscous dampers etc... But no costeffective method is available for seismic energy dissipation. When seismic energy transfers to the building, the joints like beam and column joint, brace-beam joint etc. tends to fail due to shear. To minimize this shear failures, we can provide shear fuses as energy dissipating system. The beams in which these fuses are installed is referred as "Shear Energy Dissipation Beams" (SEDB). This fuse is placed on the beam where deformations are likely to happen. When seismic energy transfers through this fuse, the fuse fails and protects the primary structure. Then, failed fuse can be replaced with another one. This shear fuses are very cost effective and cheapest method. The modelling and analysis are done using ETABs software.
Seismic Performance of Controlled Rocking Frames with Shear Fuse and PT Wire Anchorage
Journal of Structural and Construction Engineering (Transactions of AIJ), 2010
Previous studies of rocking frame systems have established their ability to resist earthquake ground motions by transforming the input energy into potential energy through uplift of the building self weight and damping out the motions through energy dissipating devices. These rocking systems are effective to minimize the residual deformation after shake and prove the resilience of a building after big earthquakes; however they have difficulty to apply to low-rise buildings because there is not enough self weight to overcome the reaction forces of energy dissipation devices. In this paper, a concept of controlling rocking deformation with additional post-tensioning (PT) wires is proposed, and its performance under various intensity levels of earthquake motions is confirmed by large-scale shaking table tests using a universal inertial mass "Testbed" system.
2020
The current state of practice for seismic design of typical buildings consider only a single design level event. The recent 2010-2011 Christchurch earthquake sequences have shown the devastating effects of sequential strong ground motion events for building structures that have not been repaired post-mainshock (MS). These events highlight the need for building structures that can be rapidly repaired while also showing the critical need to consider the seismic response of these structures for cascading large seismic events, when post-MS repairs have not occurred prior to a large aftershock(s) (AS). In recent years there has been a high interest in the development of alternative seismically resilient seismic-force resisting systems (SFRSs) that offer self-centering and rapid reparability characteristics. However, compared to conventional SFRSs, these alternative SFRSs are potentially more vulnerable to large MS-AS sequences as the energy dissipation of the replaceable structural fuses are typically substantially less than those used in conventional SFRSs. Although seismically resilient SFRSs have shown to provide excellent performance under a single design level MS, their seismic performance under cascading large earthquake sequences is not well understood. This paper presents nonlinear response history analyses results of the seismic performance of two distinctly different seismically resilient SFRSs that are expected to provide frame recentering and concentrate inelastic damage to only the replaceable structural fuses. Specifically, one frame system is detailed with post-tensioned beam-to-column joints that rock about the top flanges only with a steel plate infill web plate structural fuses. The second system is detailed with post-tensioned beam-to-column joints that rock about the top and bottom flanges with tension-compression steel structural fuses. The results presented provides some insight on the system performance and seismic resiliency of these alternative SFRSs under large MS-AS sequences.
Efficient Energy Dissipating Steel-Braced Frame to Resist Seismic Loads
Journal of Structural Engineering, 2007
In this research, the seismic performance of a proposed efficient energy dissipating steel-braced frame ͑EEDBF͒ in relation to that of a moment-resisting frame ͑MRF͒ and chevron braced frame ͑CBF͒ is studied. The frame is intended to combine the advantages of MRF and CBF and eliminate most of the disadvantages pertinent to these frames. Nonlinear static pushover, time history, and damage analyses of the three frames are conducted to assess the performance of the EEDBF compared to that of MRF and CBF. The analyses results revealed that the EEDBF has a more stable lateral force-deformation behavior compared to CBF. The energy dissipation capacity of the EEDBF is comparable to that of the MRF. The drift of the EEDBF at small to medium intensity ground motions is comparable to that of the CBF and smaller than that of the MRF. At high intensity ground motions, the drift of the EEDBF is smaller than those of both CBF and MRF. Furthermore, the EEDBF is found to experience less damage compared to other frames.
Seismic behavior of frames with innovative energy dissipation systems (FUSEIS 1-1)
Earthquakes and Structures, 2014
After strong earthquakes conventional frames used worldwide in multi-story steel buildings (e.g. moment resisting frames) are not well positioned according to reparability. Two innovative systems for seismic resistant steel frames incorporated with dissipative fuses were developed within the European Research Program "FUSEIS" (Vayas et al. 2013). The first, FUSEIS1, resembles a vertical Vierendeel beam and is composed of two closely spaced strong columns rigidly connected to multiple beams. In the second system, FUSEIS2, a discontinuity is introduced in the composite beams of a moment resisting frame and the dissipative devices are steel plates connecting the two parts. The FUSEIS system is able to dissipate energy by means of inelastic deformations in the fuses and combines ductility and architectural transparency with stiffness. In case of strong earthquakes damage concentrates only in the fuses which behave as self-centering systems able to return the structure to its initial undeformed shape. Repair work after such an event is limited only to replacing the fuses. Experimental and numerical investigations were performed to study the response of the fuses system. Code relevant design rules for the seismic design of frames with dissipative FUSEIS and practical recommendations on the selection of the appropriate fuses as a function of the most important parameters and member verifications have been formulated and are included in a Design Guide. This article presents the design and performance of building frames with FUSEIS 1-1 based on models calibrated on the experimental results.
2015
Conventional concentrically braced frame (CBF) systems have limited drift capacity prior to brace buckling, and related damage leads to deterioration in strength and stiffness. CBFs are also susceptible to weak story failure. A pinsupported self-centering frictiondamped braced frame system with buckling-restrained columns (FDBF-BRC) is being developed to provide significant drift capacity while limiting damage due to residual drift and soft-story mechanisms. The FDBF-BRC system consists of beams, columns, and braces branching off a central column, with buckling restrained columns (BRCs) incorporated into the system at the first story external column positions. The BRCs and friction generated at lateral-load bearings at each floor level are used to dissipate energy to minimize the overall seismic response of the FDBF-BRC system. Vertically aligned post-tensioning bars provide additional overturning moment resistance and aid in self-centering the system to eliminate residual drift. Th...
Dual earthquake resistant frames
Earthquake Resistant Engineering Structures VII, 2009
Structural control through energy dissipation systems has been increasingly implemented internationally in recent years and has proven to be a most promising strategy for the earthquake safety of structures. In extending the "classical" approach of the capacity design for earthquake structural resistance, the integration of passive damping devices within the structure aims at energy dissipation within specific structural zones. The present paper examines an alternative control system for achieving dynamic structural adaptability, which consists of an energy dissipation device and a cable bracing mechanism with a kinetic closed circuit, working only in tension. The closed bracing mechanism does not practically affect the initial stiffness of the system, i.e. the concept relies on two completely "separate" systems: a primary for the vertical-and wind loads and a secondary for the earthquake loads. An additional feature of the bracingdamper mechanism compared to conventionally passively controlled systems is the contribution of all bracing members to the energy dissipation during a loading cycle. Three "dual systems" with different configurations of the closed bracing mechanisms and damping devices are investigated in their dynamic behaviour, in the time-history range under actual earthquakes of the Greek-Mediterranean region. The study provides significant response comparisons of the dual systems, in respect to the stiffness of the hysteretic dampers, its effect on the base shear force and the maximum relative displacements of the systems and to the energy dissipation behaviour of the bracing-damper mechanism.