In forced vibration testing, a vibration generator bolted to one of the top floors excites the building with a known sinusoidal force. Sweeping the frequency of the vibration generator, steady-state structural responses are recorded at each operated frequency by accelerometers deployed throughout the building. Dynamic properties of the structural system are then identified from acceleration-frequency response curves by using well-established methods in the structural dynamics area, which do not require sophisticated system identification algorithms. Its drawbacks; however, have long made ambient vibration testing an attractive alternative. This study uses the ambient vibrations recorded following the forced vibration test of a four-story reinforced concrete school building with two basement floors, which is the first permanently instrumented building in Turkey and in close proximity to the North Anatolian Fault, to determine its natural vibration frequencies, modal damping capacities, and natural vibration modes. System identification using frequency domain decomposition methods yields structural system dynamic properties that are comparable to the forced vibration test results. Ambient vibration testing will be used as an alternative when building owners do not permit forced vibration testing of their buildings. The identified structural system dynamic properties will be used in calibrating the finite element structural models of the instrumented buildings in earthquake prone areas of Europe as part of a European Union project, which ultimately aims to assess their seismic fragilities.
6th International Operational Modal Analysis Conference (IOMAC)


Çelik, Ozan Cem (2017-05-12)
This paper presents a sequence of forced and ambient vibration tests performed on a six-story precast concrete building prior to any non-structural elements in place. The building is 20.2 m tall and 53.2 m by 15.8 m in plan. In forced vibration testing, the building is excited along its short and long axes, respectively, by a fifth-floor level vibration generator with a known sinusoidal force. Sweeping the vibration generator frequency from 0.5 to 9.5 Hz, structural vibrations are recorded by a dense networ...
Effect of AAC Infill Walls on Structural System Dynamics of a Concrete Building
Çelik, Ozan Cem (2016-01-01)
The effect of autoclaved aerated concrete (AAC) infill walls on the structural system dynamics of a two-story reinforced concrete building is investigated using its finite element structural model, which is calibrated to simulate the acceleration-frequency response curves from its forced vibration test. The model incorporating the AAC infill walls by equivalent diagonal struts captures the increase in lateral stiffness of the building and the torsional motions induced due to the asymmetrically placed AAC in...
Evaluation of floor vibration in an existing building
Semerdöken, Yavuz; Yakut, Ahmet; Department of Civil Engineering (2019)
Vibration serviceability is a major concern in the design of lighter floor systems of newer buildings. Floor vibrations due to walking and rhythmic movements of the occupants should not exceed threshold levels for the comfort of occupants and the protection of sensitive equipment in the buildings. The objective of this study is to evaluate the floor vibration problem reported in a six-story reinforced concrete with two basement floors office building. First, structural system dynamic properties of the build...
Forced Vibration Testing and Seismic Fragility Assessment of Instrumented Structures (FORAGAINST)
Çelik, Ozan Cem(2016-2-07)
The objectives of this proposed research are to perform forced vibration tests on the following reinforced concrete structures, which are permanently instrumented for recording their dynamic responses in the case of future earthquakes in Turkey: a four-story dormitory building in Bolu, a four-story office building in Istanbul, a five-story hospital building in Antakya, a three-story school building in Antakya, and a four-story university building in Izmir, and to derive seismic fragilities for these structu...
Natural periods of steel plate shear wall systems
Topkaya, Cem (Elsevier BV, 2009-03-01)
in most seismic building codes, the design base acceleration is computed using the natural period of vibration of the structure. Design specifications provide empirical formula to estimate the fundamental natural period of a system. In this study a class of steel plate shear walls, that have uniform properties through their height, was considered. The fundamental natural periods of this class of structures were determined using three dimensional geometrically linear finite element analyses and were compared...
Citation Formats
O. C. Çelik, “AMBIENT VIBRATION RECORDS IN REPRODUCING THE FORCED VIBRATION TEST RESULTS OF A FOUR-STORY REINFORCED CONCRETE BUILDING WITH TWO BASEMENT FLOORS,” presented at the 6th International Operational Modal Analysis Conference (IOMAC), Gijon, SPAIN, 2015, Accessed: 00, 2020. [Online]. Available: