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ABSTRACT This study integrates analytical and experimental research to develop an innovative shake table testing method called Floor Acceleration Simulation Test (FAST). The primary objective of FAST is to produce an essentially elastic response of a single‐story test specimen to replicate the floor acceleration time history including higher‐mode effects of a target floor in a multistory building experiencing inelastic behavior during an earthquake. The FAST method is well suited for experimental research where the absolute accelerations and the associated inertial forces of the floor diaphragms cannot be simulated by the majority of the conventional test methods. The proposed methodology is based on a transfer function in the frequency domain to compute the required input motion for testing. Considering the physical constraints of a given shake table test facility, guidelines with two response spectra to bracket the natural frequency of the test building are also presented for practical implementation. Experimental validation was carried out on a half‐scale, single‐story steel building featuring a composite floor slab, utilizing the NHERI@UCSD Large High‐Performance Outdoor Shake Table (LHPOST) facility. The results demonstrate the effectiveness of FAST, as both analytical predictions and experimental outcomes confirm its validity. Despite instances of measured floor acceleration amplitude exceeding the target response due to table input motion overshooting in this test program, test results confirmed that the FAST accurately reproduced the intended frequency content, indicative of higher mode effects in the multistory prototype building, in the single‐story test building.
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Phase 1: Single-Story Testing for Development of Floor Acceleration Simulation Methodology, in Advancing Knowledge on the Performance of Seismic Collectors in Steel Building Structures: Shake Table Tests
Phase 1 used a single-story steel test building with a composite slab and perimeter collectors to develop and validate a Floor Acceleration Simulation Testing (FAST) methodology intended to reproduce multistory floor accelerations in a single-story test frame. White-noise and impulse tests were used to identify dynamic properties, followed by earthquake simulation tests at 20%, 50%, and 100% Design Earthquake (DE) levels to observe collector axial force, slab participation, and connection rotation. White-noise tests: White-noise excitation was applied at low amplitude to identify the natural frequencies, damping ratios, and stiffness characteristics of the structure. These tests were typically conducted before and after earthquake events to track changes in dynamic properties as damage accumulated. Impulse tests: Single-pulse excitation was applied through the shake table to evaluate the transient dynamic characteristics of the structure and to supplement the system-identification testing performed using white-noise input. Floor Acceleration Simulation Testing (FAST): In FAST, the objective was to reproduce realistic multistory floor acceleration demands in a single-story test building. Target floor-acceleration histories were obtained from nonlinear response-history analyses of a 12-story BRBF prototype building (SDII). A transfer-function approach in the frequency domain was then used to compute the shake-table input motion required for the single-story specimen to generate these target accelerations. This approach allowed the specimen to respond essentially elastically while reproducing the amplitude and frequency content of multistory floor accelerations. Earthquake simulation tests: Earthquake events consisted of acceleration time histories based on the 1994 Northridge Earthquake record (Beverly Hills-14145 Mulhol.), scaled to different Design Earthquake (DE) intensity levels. Motions were applied in both direct and sign-reversed directions. These events were used to evaluate collector forces, slab parti
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- Award ID(s):
- 1662816
- PAR ID:
- 10661889
- Publisher / Repository:
- Designsafe-CI
- Date Published:
- Edition / Version:
- 1
- Subject(s) / Keyword(s):
- Collectors seismic collectors collector connections floor diaphragms composite slab steel buildings shake table testing floor acceleration simulation inertial force NHERI@UC San Diego Large High Performance Outdoor Shake Table (LHPOST)
- Format(s):
- Medium: X
- Institution:
- UCSD, University of Arizona
- Sponsoring Org:
- National Science Foundation
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