Performance of a damage‐protected beam–column subassembly utilizing external HF2V energy dissipation devices

Abstract

9SUMMARY Ductile-jointed connections, which generally require some form of supplementary energy dissipation to 11 alleviate displacement response, typically employ mild steel energy dissipation devices. These devices run the risk of low-cycle fatigue, are effective only for peak cycles that exceed prior displacements, are prone 13 to buckling, and may require replacement following an earthquake. This study presents an experimental investigation employing an alternative to mild steel: a high force-to-volume (HF2V) class of damper-based 15 energy dissipation devices. Tests are performed on a near full-scale beam-column joint subassembly utilizing externally mounted compact HF2V devices. Two configurations are considered: an exterior joint 17 with two seismic beams and one gravity beam framing into a central column, and a corner joint with only one seismic beam and one gravity beam framing into a column. Quasi-static tests are performed to 19 column drifts up to 4%. The experiments validate the efficacy of the HF2V device concept, demonstrating good hysteretic energy dissipation, and minimal residual device force, allowing ready re-centring of the 21 joint. The devices dissipate energy consistently on every cycle without the deterioration observed in the yielding steel bar type of devices. The effectiveness of the HF2V devices on structural hysteretic behavior 23 is noted to be sensitive to the relative stiffness of the anchoring elements, indicating that better efficiency would be obtained in an embedded design.

Experimentally validated FEA models of HF2V damage free steel connections for use in full structural analyses

“…Similar results are obtained for the concrete connections, compared to similar reinforced concrete connections, for the tests in Fig. 3 (Rodgers et al 2008b, Solberg 2007. Hence, using these devices can provide more efficient energy dissipation without yielding damage to the connection, and can do so every cycle regardless of prior motions or drifts.…”

“…3 shows the external test case with devices circled (Rodgers et al 2008b, Solberg 2007. The devices have also been successfully tested in a 50% full scale steel beam-column joint, as seen in Fig.…”

Earthquake Protection of Existing Structures with Limited Seismic Joint: Base Isolation with Supplemental Damping versus Rotational Inertia

“…Among these strategies, we mention the coupling of adjacent buildings by means of passive damping devices to reduce the risk of pounding [50][51][52] and to improve the seismic performance of the two systems [53][54][55], the introduction of viscous dampers along the height of the building that produce desired levels of interstory drifts while reducing seismic forces [56,57], the interstory isolation by the use of seismic isolators at levels other than the base along the height of a building [58,59], and the interstory isolation implemented by converting masses already present on the structure into tuned masses according to a nonconventional TMD scheme [38,60]. Moreover, there are a range of supplemental dampers that do not have a viscous nature, for example, buckling restrained braces, yielding fuse systems, and the HF2V device based on the lead extrusion technology [61][62][63][64], to quote just a few. In these cases, the simplified assumption of a linear viscous damping, made throughout this paper, does not apply, and one should consider a more complicated constitutive behavior, which is beyond the scope of the present study.…”

Semi‐explicit rate‐dependent modeling of damage‐avoidance steel connections using HF2V damping devices

“…The experimental results of Figure 6 show that an external force is required to return the connection to the original zero-displacement position. While other concrete and steel connections that utilize post-tensioned prestressing bars have been tested which exhibit self-centering characteristics (Garlock et al 2007;Rodgers et al 2008b), that is not the focus of this specimen. Therefore, as this connection design does not provide static re-centering capability, this type of connection must be considered as part of a larger structural system.…”

“…These devices have been implemented into several large-scale experiments, using both jointed-precast concrete and steel beam-to-column rigid connections (Mander et al 2009;Rodgers et al 2008b). During these experimental investigations it has become apparent that the influence of connecting elements has a large effect on the connection rigidity and energy dissipation capacity of the damping system.…”