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Steel-deck composite floor systems are being increasingly used in high-rise building construction, especially in Australia, as they are economical and easy to construct. These composite floor systems use high strength materials to achieve longer spans and are thus slender. As a result, they are vulnerable to vibration induced under service loads. These floors are normally designed using static methods which will not reveal the true behaviour and miss the dynamic amplifications resulting in inappropriate designs, which ultimately cause vibration and discomfort to occupants. At present there is no adequate design guidance to address the vibration in these composite floors, due to a lack of research information, resulting in wasteful post event retrofits. To address this gap in knowledge, a comprehensive research project is presented in this thesis, which investigated the dynamic performance of composite floors under various human induced loads. A popular type of composite floor system was selected for this investigation and subjected to load models representing different human activities. These load models have variable parameters such as load intensity, activity type (contact ratio), activity frequency and damping and are applied as pattern loads to capture the maximum responses in terms of deflections and accelerations. Computer models calibrated against experimental results are used in the analysis to generate the required information. The dynamic responses of deflections and accelerations are compared with the serviceability deflection limits and human comfort levels (of accelerations) to assess these floor types. This thesis also treats the use of visco-elastic (VE) dampers to mitigate excessive vibrations in steel-deck composite floors. VE damper properties have been presented and their performances in reducing the excessive vibrations have been assessed this thesis. The results identified possible occupancies under different loading conditions that can be used in planning, design and evaluation. The findings can also be used to plan retrofitting measures in problematic floor systems.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Um aumento crescente dos problemas estruturais associados à vibração excessiva de pisos de edificações de estruturas mistas (aço-concreto) e de concreto armado devido a atividades humanas rítmicas constitui a principal motivação para o desenvolvimento de uma metodologia de projeto respaldada na obtenção da resposta dinâmica de pisos mistos (aço-concreto) e de concreto armado, quando submetidos a cargas dinâmicas humanas rítmicas. Para tal, os modelos estruturais estudados baseiam-se em pisos de edificações mistas (aço-concreto) e de concreto armado submetidos a aulas de ginástica aeróbica. São empregadas técnicas usuais de discretização, via método dos elementos finitos (MEF), por meio do programa ANSYS. Um estudo paramétrico foi realizado sobre os modelos estruturais investigados e foram obtidos valores elevados para as acelerações de pico violando os critérios de projeto e indicando níveis de vibrações excessivas. Considerando-se os aspectos mencionados anteriormente foi desenvolvida uma estratégia com base em alternativas viáveis para o controle estrutural, objetivando a atenuação das vibrações excessivas a partir da instalação de atenuadores dinâmicos sincronizados (ADS) nos pisos analisados. / The increasing incidence of building vibration problems due to human rhythmic activities led to a specific design criterion to be addressed in structural design. This was the main motivation for the development of a design methodology centred on the composite (steel-concrete) and reinforced concrete building floors dynamic response when submitted to dynamic loads due to human rhythmic activities. The structural system is composed by a composite (steel-concrete) and a reinforced concrete building floor subjected to aerobics. The proposed analysis methodology adopted the usual mesh refinement techniques present in the finite element method (FEM) simulations implemented in the ANSYS program. An extensive parametric study was developed and the results have demonstrated that the analysed composite and reinforced floor have presented high values of accelerations and excessive vibrations. Considering all aspects mentioned before, it was developed a structural control strategy aiming to reduce the floor excessive vibrations. Finally, an investigation was performed based on some structural control alternatives for attenuating excessive vibrations using Tuned Mass Damper (TMD) systems.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Um aumento crescente dos problemas estruturais associados à vibração excessiva de pisos de edificações de estruturas mistas (aço-concreto) e de concreto armado devido a atividades humanas rítmicas constitui a principal motivação para o desenvolvimento de uma metodologia de projeto respaldada na obtenção da resposta dinâmica de pisos mistos (aço-concreto) e de concreto armado, quando submetidos a cargas dinâmicas humanas rítmicas. Para tal, os modelos estruturais estudados baseiam-se em pisos de edificações mistas (aço-concreto) e de concreto armado submetidos a aulas de ginástica aeróbica. São empregadas técnicas usuais de discretização, via método dos elementos finitos (MEF), por meio do programa ANSYS. Um estudo paramétrico foi realizado sobre os modelos estruturais investigados e foram obtidos valores elevados para as acelerações de pico violando os critérios de projeto e indicando níveis de vibrações excessivas. Considerando-se os aspectos mencionados anteriormente foi desenvolvida uma estratégia com base em alternativas viáveis para o controle estrutural, objetivando a atenuação das vibrações excessivas a partir da instalação de atenuadores dinâmicos sincronizados (ADS) nos pisos analisados. / The increasing incidence of building vibration problems due to human rhythmic activities led to a specific design criterion to be addressed in structural design. This was the main motivation for the development of a design methodology centred on the composite (steel-concrete) and reinforced concrete building floors dynamic response when submitted to dynamic loads due to human rhythmic activities. The structural system is composed by a composite (steel-concrete) and a reinforced concrete building floor subjected to aerobics. The proposed analysis methodology adopted the usual mesh refinement techniques present in the finite element method (FEM) simulations implemented in the ANSYS program. An extensive parametric study was developed and the results have demonstrated that the analysed composite and reinforced floor have presented high values of accelerations and excessive vibrations. Considering all aspects mentioned before, it was developed a structural control strategy aiming to reduce the floor excessive vibrations. Finally, an investigation was performed based on some structural control alternatives for attenuating excessive vibrations using Tuned Mass Damper (TMD) systems.