On‐line hybrid test method for evaluating the performance of structural details to failure

Self Cite

This study develops a generalised multi‐hazard analysis framework for evaluating the impact of secondary hazard events on structures that have previously been damaged by major hazardous events. More specifically, the present work investigates the effects of thunderstorm downbursts on earthquake‐damaged tall steel buildings giving an emphasis in assessing the revised accumulated earthquake‐wind ductility demands. The novel approach is validated on a 20‐storey steel building. The structure is initially subjected to a ductility‐controlled pushover analysis to simulate the earthquake‐induced damage, and then, a parametric dynamic analysis is performed using damaged structure models under synthetic downburst time‐histories developed for various wind profiles, wind velocities and terrain types. The method accurately controls the damage level induced by the primary hazard and separately assesses secondary hazard effects which enables a direct quantification of the new multi‐hazard design requirements. This can provide effective guidance in the stage of preliminary structural design or post‐hazard assessment of structures identifying new serviceability limits, as well as support repair procedures and decision‐making frameworks for existing structures to prevent collapse. The results demonstrate a significant increase up to three to four times in ductility demands of the structure after the occurrence of the strong downburst winds, compared with the ductility demands that were initially imposed by the varying severity degrees of the earthquake.

Section: Multi‐hazard Analysis Frameworkmentioning

confidence: 99%

Section: Multi-hazard Analysis Frameworkmentioning

confidence: 99%

A multi‐hazard analysis framework for earthquake‐damaged tall buildings subject to thunderstorm downbursts

Song

Skalomenos

Martínez-Vázquez

2023

Self Cite

“…As shown in Figure 3B, b cut and h cut represent the lengths of the two right-angle sides of the cutting triangles. The length of b cut can be obtained as Equation (5).…”

Section: Modification Of the Restraining Platesmentioning

confidence: 99%

“…Dampers are energy dissipation components that can protect the structural system from damage by absorb some of the input earthquake energy 1–5 . As one type of the widely used dampers, the steel shear panel damper (SPD) dissipate energy through the in‐plane shear yield deformation of the panel.…”

Section: Introductionmentioning

confidence: 99%

“…Dampers are energy dissipation components that can protect the structural system from damage by absorb some of the input earthquake energy. [1][2][3][4][5] As one type of the widely used dampers, the steel shear panel damper (SPD) dissipate energy through the in-plane shear yield deformation of the panel. Owing to the merits such as simple design, good energy dissipation capacity, and low cost, SPDs have received increasing attentions, and have been applied in buildings and bridges.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical properties of a novel buckling restrained shear panel damper with octagon restraining plates

Lin

Yin

et al. 2021

Steel shear panel dampers (SPDs) have been widely used for the seismic protection of structures. The seismic performance of SPD is limited by the buckling deformation and low cycle fatigue tearing of the web. This study proposes a newtype buckling restrained shear panel damper (BRSPD), in which two octagon restrainers are utilized instead of rectangular ones. The novel BRSPD is developed to prevent its web plate from stress concentration and tearing at the early stage. A basic mechanism for the novel BRSPD was proposed. Quasi-static tests were conducted to examine the behavior of the BRSPDs. The influence of the factors, such as the configurations of the restrainers and the gap size between the restrainer and the web plate, were investigated. The experimental results indicated that the proposed octagon restrainers can effectively restrain the out-ofplane deformation of the web plate. The BRSPDs with the proposed restrainers presented better energy dissipation performance than both the conventional SPD and those with rectangular restraining plates. The shape and the thickness of the restrainers had significant influence on the performance of the damper, while adding grease or rubber between the restrainer and web plate had little effect.The BRSPD with no gap between the plates had the highest equivalent viscous damping ratio.

Collapse hybrid simulation for testing steel building columns subject to boundary condition changes

Skalomenos,

Kurata

2024

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This paper develops a hybrid simulation to experimentally evaluate the ultimate behavior of steel columns subject to boundary condition changes and bending moment redistribution due to the progressive seismic collapse of building structures. The proposed experimental method combines sub‐structuring test techniques and refined finite element (FE) analysis methods in a hybrid scheme. The inelastic behavior of steel moment‐resisting‐frames (MRF) is computationally simulated while ground‐floor columns are physically tested online with the FE frame analysis. Boundary conditions at the interface node between the column test and the frame analysis are reproduced with the aid of three actuators that impose axial loads and bending deformations to the column test. Two square tubular steel columns are tested as part of a five‐storey five‐bay steel MRF designed to employ two different heights of the ground floor (i.e., 4.6 and 5.1 m, respectively). The hybrid simulation revealed that individual failures of the peripherical frame members significantly alter the distribution of the bending moment along the height of the column test, thus changing the boundary conditions at its top end. The imposed moment distribution was further influenced by local buckling initiated at the base of the column test and ground‐floor beams and could cause the top end of the upper‐storey columns of the frame to buckle. In the MRF with 4.6 m‐height ground‐floor, this resulted in a global collapse mechanism that involved the ground floor and the second storey. In the MRF with 5.1 m‐height ground‐floor, a weak‐storey collapse mechanism was formed within the ground floor. Compared to a corresponding isolated column tested as cantilever using conventional methods, the columns tested with the proposed hybrid simulation exhibited a more favorable inelastic behavior primarily due to the more realistic loads and changes of boundary conditions which are ignored in conventional test methods.