Response of infilled frames using pseudo-dynamic experimentation

SUMMARY This paper presents the results of an experimental study on the determination of damping characteristics of bare, masonry infilled, and carbon fiber reinforced polymer retrofitted infilled reinforced concrete (RC) frames. It is well known that the masonry infills are used as partitioning walls having significant effect on the damping characteristics of structures as well as contribution to the lateral stiffness and strength. The main portion of the input energy imparted to the structure during earthquakes is dissipated through hysteretic and damping energies. The equivalent damping definition is used to reflect various damping mechanisms globally. In this study, the equivalent damping ratio of carbon fiber reinforced polymer retrofitted infilled RC systems is quantified through a series of 1/3‐scaled, one‐bay, one‐story frames. Quasi‐static tests are carried out on eight specimens with two different loading patterns: one‐cycled and three‐cycled displacement histories and the pseudo‐dynamic tests performed on eight specimens for selected acceleration record scaled at three different PGA levels with two inertia mass conditions. The results of the experimental studies are evaluated in two phases: (i) equivalent damping is determined for experimentally obtained cycles from quasi‐static and pseudo‐dynamic tests; and (ii) an iterative procedure is developed on the basis of the energy balance formulation to determine the equivalent damping ratio. On the basis of the results of these evaluations, equivalent damping of levels of 5%, 12%, and 14% can be used for bare, infilled, and retrofitted infilled RC frames, respectively. Copyright © 2013 John Wiley & Sons, Ltd.

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“…Mosalam et al . performed PsD tests on a two‐bay, two‐story steel structure. The test results were evaluated in terms of energy concepts.…”

Section: Proposed Approach To Determine the Equivalent Damping Ratio mentioning

confidence: 99%

Masonry infill walls in reinforced concrete frames as a source of structural damping

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et al. 2013

Earthq Engng Struct Dyn

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“…However, as demonstrated by many researchers [1][2][3][4][5], infill panels may completely alter the structural behaviour by their non-negligible bracing actions during strong earthquake excitation. The cost-effective, easy construction and flexible layout characteristics of masonry infill panels make them a popular choice for architects to arrange interior and exterior partitions.…”

Section: Introductionmentioning

confidence: 99%

Low‐seismic damage strategies for infilled RC frames: shake‐table tests

Zhang

Kuang

Yuen

2017

Earthq Engng Struct Dyn

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Summary Unreinforced masonry (URM) infill panels are widely used as partitions in RC frames and typically considered as non‐structural elements in the design process. However, observations from recent major earthquakes have shown that under seismic excitation, the structural interaction between columns and infill walls can significantly alter the structural behaviour, thus causing catastrophic consequences. The purpose of this research was to propose and test an innovative low seismic damage detailing method, which isolates the infill panel from bounding columns with finite width vertical gaps during the infill panel construction phase and deploys steel wire connections in mortar layers anchored to columns. Taking into account the similitude requirements, a total of six one‐third scale, single‐storey single‐bay RC frames with different infill configurations and flexible connection details were carefully designed and tested on a shake‐table. Three real earthquake records were selected and scaled to ascending intensity levels and used as input signals. A series of thorough investigations including dynamic characteristics, hysteretic behaviour, failure mechanisms, out‐of‐plane vulnerabilities and the effect of different gap filling materials and load transfer mechanisms were rigorously studied. The experimental results indicate that the undesirable interaction between infill panels and bounding frame is significantly reduced using the proposed low seismic damage detailing concept. Direct shear failure of columns at an early stage is prevented, and structural redundancy at high levels of excitation can be provided. In general, the structural stability and integrity, and displacement ductility of infilled RC frames can remarkably be improved. Copyright © 2017 John Wiley & Sons, Ltd.

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“…For instance, a full‐scale four‐story infilled RC frame structure was proposed to verify the reliability of pseudo‐dynamic testing result by Donea et al . Mosalam et al . experimentally tested a two‐story two‐bay steel frame infilled with unreinforced concrete block masonry by using pseudo‐dynamic testing.…”

Section: Introductionmentioning

confidence: 99%

Real-time hybrid testing of a structure with a piezoelectric friction controllable mass damper by using a shake table

Chu

Yeh

2017

Struct Control Health Monit

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Summary A structure with semi‐active control devices is usually a highly nonlinear system. To investigate the aseismic performance of such a system, real‐time hybrid testing (RTHT) can be a cost‐effective experimental method. However, a substructure with a semi‐active friction device is difficult to be tested by the RTHT, because the dynamic behavior of a friction device, which consists of sliding and sticking phases, is determined by the exerted force of the primary structure, rather than its displacement response. To overcome this problem, a methodology of RTHT with a shake table (RTHT‐ST) is utilized in this study. In the RTHT‐ST, which is an experimental technique combining shaking table test and RTHT, the shake table is employed to mimic the acceleration response of the primary structure that is simulated by a numerical model and imposed to the substructure, which is mounted on the shake table. In order to verify the feasibility of the experimental method, a semi‐active piezoelectric friction controllable mass damper substructure is tested by using the RTHT‐ST. The test results of the RTHT‐ST are compared with those of a full shaking table test, in which the integrated primary structure and piezoelectric friction controllable mass damper system have been physically tested. Moreover, to evaluate the accuracy of the RTHT‐ST result, one category of indicators called root‐mean‐square energy error index is also proposed. Unlike previously existing hybrid‐testing indices, the root‐mean‐square energy error index is able to distinguish modeling error from control system error.

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Response of infilled frames using pseudo-dynamic experimentation

Cited by 39 publications

References 12 publications

Masonry infill walls in reinforced concrete frames as a source of structural damping

Masonry infill walls in reinforced concrete frames as a source of structural damping

Low‐seismic damage strategies for infilled RC frames: shake‐table tests

Real-time hybrid testing of a structure with a piezoelectric friction controllable mass damper by using a shake table

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