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Mehdi Setareh - One of the best experts on this subject based on the ideXlab platform.

  • semiactive tuned mass damper for Floor Vibration control
    Journal of Structural Engineering-asce, 2007
    Co-Authors: Mehdi Setareh, Thomas M. Murray, John K. Ritchey, Jeonghoi Koo, Mehdi Ahmadian
    Abstract:

    A semiactive magnetorheological device is used in a pendulum tuned mass damper (PTMD) system to control the excessive Vibrations of building Floors. This device is called semiactive pendulum tuned mass damper (SAPTMD). Analytical and experimental studies are conducted to compare the performance of the SAPTMD with its equivalent passive counterpart. An equivalent single degree of freedom model for the SAPTMD is developed to derive the equations of motion of the coupled SAPTMD-Floor system. A numerical integration technique is used to compute the Floor dynamic response, and the optimal design parameters of the SAPTMD are found using an optimization algorithm. Effects of off-tuning due to the variations of the Floor mass on the performance of the PTMD and SAPTMD are studied both analytically and experimentally. From this study it can be concluded that for the control laws considered here an optimum SAPTMD performs similarly to its equivalent PTMD, however, it is superior to the PTMD when the Floor is subjected to off-tuning due to Floor mass variations from sources other than human presence. It is also found that for the case of off-tuning due to Floor mass variations from the human occupants when the human-structure dynamic interactions are not considered in the analytical modeling, large inconsistencies between the analytical and experimental results can be expected.

  • Pendulum Tuned Mass Dampers for Floor Vibration Control
    Journal of Performance of Constructed Facilities, 2006
    Co-Authors: Mehdi Setareh, John K. Ritchey, Anthony J. Baxter, Thomas M. Murray
    Abstract:

    This paper presents the results of the analytical and experimental studies of a pendulum tuned mass damper (PTMD) to control excessive Floor Vibrations due to human movements. The PTMD used in this study acts as a passive tuned mass damper. An equivalent single-degree-of-freedom model for the PTMD is developed and used to derive the equations of motion of the coupled PTMD-Floor system. The optimal design parameters of the PTMD are found using an optimization algorithm. Effects of off-tuning of the PTMD due to the variations in the Floor mass on its response are investigated. Results of the tuning of the PTMD on a laboratory test Floor are presented along with the off-tuning effects. These results indicate that a properly tuned PTMD can significantly reduce the excessive Floor Vibrations. In addition, when subjected to off-tuning due to variations in the Floor live load the PTMD may or may not be able to perform effectively depending on the level of human-structure dynamic interactions. Finally, examples o...

  • Floor Vibration control using semi active tuned mass dampers
    Canadian Journal of Civil Engineering, 2002
    Co-Authors: Mehdi Setareh
    Abstract:

    This paper discusses the application of a new class of semi-active tuned mass dampers, called ground-hook tuned mass dampers (GHTMD), for the reduction of Floor Vibrations due to human movements. The TMD introduced uses a continuously variable semi-active damper (ground-hook damper) to achieve reduction in the Floor acceleration. Here, the GHTMD is applied to a single degree of freedom system representative of building Floors. The GHTMD design parameters are defined in terms of non-dimensional values. The optimum values of these parameters are found based on the minimization of the acceleration response of the Floor for different GHTMD mass ratios and Floor damping ratios. The performance of the GHTMD is compared to that of the equivalent passive TMD. In addition, the effects of off-tuning due to variations in the mass ratios and frequency ratios of the TMD and GHTMD are studied. Comparison of the results demonstrates the efficiency and robustness of GHTMD with respect to equivalent TMD. Finally, a guide ...

  • tuned mass dampers to control Floor Vibration from humans
    Journal of Structural Engineering-asce, 1992
    Co-Authors: Mehdi Setareh, Robert D Hanson
    Abstract:

    The Vibration of Floor systems caused by human movements can be reduced using tuned mass dampers. The component mode synthesis (CMS) method is used to compute the response of the Floor‐tuned mass damper system using only a few natural modes of the Floor. Models representing typical two‐dimensional Floor‐system behavior are used to illustrate this technique. Tuning parameters obtained using the CMS method and an equivalent single degree of freedom (SDOF) model to represent the Vibration characteristics of a multiple degree of freedom system are compared. It is found that using the CMS method can result in the optimum parameters of the tuned mass dampers regardless of the closeness of the natural frequencies of the system. This is not the case when the equivalent SDOF model is used. Therefore, it is concluded that use of CMS method to represent the model for optimization produces tuned mass damper parameters that provide global reduction in the amplitude of Vibration for cases with and without closely space...

Jacob C Lindeman - One of the best experts on this subject based on the ideXlab platform.

  • haptic chairio a system to study the effect of wind and Floor Vibration feedback on spatial orientation in ves
    Symposium on 3D User Interfaces, 2015
    Co-Authors: Mi Feng, Robert W Lindeman, Hazem Abdelmoati, Jacob C Lindeman
    Abstract:

    In this poster, we present the design, implementation, and evaluation plan of a system called Haptic ChairIO. A design space is first introduced, classifying sensory cues, and describing the potential usage of haptic cues on cognitive tasks in virtual environments (VEs). Then follows the design and implementation of Haptic ChairIO, which is extendable in providing various sensory cue types, consisting of a VR simulation, chair-based motion-control input, and multi-sensory output, including visual, audio, wind, and Floor Vibration feedback. A plan of evaluation has been made to study the effect of wind and Floor Vibration on spatial orientation in VEs.

  • 3DUI - Haptic ChairIO: A system to study the effect of wind and Floor Vibration feedback on spatial orientation in VEs
    2015 IEEE Symposium on 3D User Interfaces (3DUI), 2015
    Co-Authors: Mi Feng, Robert W Lindeman, Hazem Abdel-moati, Jacob C Lindeman
    Abstract:

    In this poster, we present the design, implementation, and evaluation plan of a system called Haptic ChairIO. A design space is first introduced, classifying sensory cues, and describing the potential usage of haptic cues on cognitive tasks in virtual environments (VEs). Then follows the design and implementation of Haptic ChairIO, which is extendable in providing various sensory cue types, consisting of a VR simulation, chair-based motion-control input, and multi-sensory output, including visual, audio, wind, and Floor Vibration feedback. A plan of evaluation has been made to study the effect of wind and Floor Vibration on spatial orientation in VEs.

Thomas M. Murray - One of the best experts on this subject based on the ideXlab platform.

  • Solving Floor Vibration Problems Using Dynamic Analysis and Testing
    Structures Congress 2013, 2013
    Co-Authors: Brad Davis, Di Liu, Thomas M. Murray
    Abstract:

    It is sometimes necessary to provide retrofit solutions to objectionable Floor Vibrations due to human activity. Because such problems are usually detected after the design and construction phases are complete, and the owners have occupied the building, the evaluation of retrofit options must be fast and economical. This paper describes a framework for evaluating retrofit options and presents a case study.

  • Floor Vibration CHARACTERISTICS OF LONG SPAN COMPOSITE SLAB SYSTEMS
    Structures Congress 2011, 2011
    Co-Authors: T Andres Sanchez, Brad Davis, Thomas M. Murray
    Abstract:

    Recently developed steel-framed Floor systems utilizing long-span metal deck have the potential of providing large column free areas with overall Floor thicknesses approximately equal to concrete flat plates while typically imposing less dead load on the structure. The Vibration serviceability of such Floor systems is investigated in this paper. Two laboratory specimens, a full-scale mockup, and 13 in-situ Floors were tested to measure their natural modes and responses to walking excitations. Natural modes were determined using experimental modal analysis techniques or heel-drop test results. Response to walking was determined by measuring the maximum peak acceleration due to individual walkers traversing the Floor. The natural frequencies for the laboratory specimens and mockup were in the range of those measured for typical composite framing systems whereas all in-situ Floors are high-frequency Floors. The measured accelerations due to walking and subjective evaluations indicate that such Floors will generally have adequate resistance to Vibrations due to walking.

  • semiactive tuned mass damper for Floor Vibration control
    Journal of Structural Engineering-asce, 2007
    Co-Authors: Mehdi Setareh, Thomas M. Murray, John K. Ritchey, Jeonghoi Koo, Mehdi Ahmadian
    Abstract:

    A semiactive magnetorheological device is used in a pendulum tuned mass damper (PTMD) system to control the excessive Vibrations of building Floors. This device is called semiactive pendulum tuned mass damper (SAPTMD). Analytical and experimental studies are conducted to compare the performance of the SAPTMD with its equivalent passive counterpart. An equivalent single degree of freedom model for the SAPTMD is developed to derive the equations of motion of the coupled SAPTMD-Floor system. A numerical integration technique is used to compute the Floor dynamic response, and the optimal design parameters of the SAPTMD are found using an optimization algorithm. Effects of off-tuning due to the variations of the Floor mass on the performance of the PTMD and SAPTMD are studied both analytically and experimentally. From this study it can be concluded that for the control laws considered here an optimum SAPTMD performs similarly to its equivalent PTMD, however, it is superior to the PTMD when the Floor is subjected to off-tuning due to Floor mass variations from sources other than human presence. It is also found that for the case of off-tuning due to Floor mass variations from the human occupants when the human-structure dynamic interactions are not considered in the analytical modeling, large inconsistencies between the analytical and experimental results can be expected.

  • Pendulum Tuned Mass Dampers for Floor Vibration Control
    Journal of Performance of Constructed Facilities, 2006
    Co-Authors: Mehdi Setareh, John K. Ritchey, Anthony J. Baxter, Thomas M. Murray
    Abstract:

    This paper presents the results of the analytical and experimental studies of a pendulum tuned mass damper (PTMD) to control excessive Floor Vibrations due to human movements. The PTMD used in this study acts as a passive tuned mass damper. An equivalent single-degree-of-freedom model for the PTMD is developed and used to derive the equations of motion of the coupled PTMD-Floor system. The optimal design parameters of the PTMD are found using an optimization algorithm. Effects of off-tuning of the PTMD due to the variations in the Floor mass on its response are investigated. Results of the tuning of the PTMD on a laboratory test Floor are presented along with the off-tuning effects. These results indicate that a properly tuned PTMD can significantly reduce the excessive Floor Vibrations. In addition, when subjected to off-tuning due to variations in the Floor live load the PTMD may or may not be able to perform effectively depending on the level of human-structure dynamic interactions. Finally, examples o...

  • Controlling Floor Vibration with Active and Passive Devices
    The Shock and Vibration Digest, 2003
    Co-Authors: Linda M. Hanagan, Thomas M. Murray, Kamal Premaratne
    Abstract:

    This paper reviews research, conducted by the authors over the last decade, pertaining to the control of ex- cessive Floor Vibration using active and passive devices. The active device studied uses a proof-mass actuator to deliver the control force to the Floor system. Effectiveness and stabil- ity characteristics for a single-input/single-output (SISO) con- trol scheme, using velocity feedback, are explored. The SISO system is shown to increase damping to 40% of critical on an experimental Floor when amplitudes remain in the linear range. When implemented on two in-place Floors, at least a 70% reduction in Vibration amplitudes due to walking was ob- served. Next, the benefits of expanding to a practical single- input/multi-output (SIMO) control system are identified. Ad- ditionally, techniques to optimize the SIMO scheme are presented. Because of the stability characteristics of the controlled system, the improvement noted for the SIMO scheme is most dramatic for Floors with fundamental frequen- cies near the natural frequency of the actuator. I na2H zFloor example, a SIMO control scheme provided seven times more reduction than that of the SISO system. The passive device research focuses on the experimental implementation of tuned mass dampers (TMDs) to control Floor Vibration. Two different configurations are explored. The uniqueness of the first device is that liquid filled bladders are used to provide an economical damping mechanism. When implemented on an office Floor, a significant improvement of walking Vibration lev- els was observed. Satisfaction with the repair was noted from the occupants. The second device utilizes a configuration that has great flexibility in the field, thus allowing for more eco- nomical mass production. Using two TMDs, a significant re- duction of response was noted for the 5 and 6 Hz modes. Research to improve these active and passive strategies continues and will be reported as significant results are achieved.

Mi Feng - One of the best experts on this subject based on the ideXlab platform.

  • haptic chairio a system to study the effect of wind and Floor Vibration feedback on spatial orientation in ves
    Symposium on 3D User Interfaces, 2015
    Co-Authors: Mi Feng, Robert W Lindeman, Hazem Abdelmoati, Jacob C Lindeman
    Abstract:

    In this poster, we present the design, implementation, and evaluation plan of a system called Haptic ChairIO. A design space is first introduced, classifying sensory cues, and describing the potential usage of haptic cues on cognitive tasks in virtual environments (VEs). Then follows the design and implementation of Haptic ChairIO, which is extendable in providing various sensory cue types, consisting of a VR simulation, chair-based motion-control input, and multi-sensory output, including visual, audio, wind, and Floor Vibration feedback. A plan of evaluation has been made to study the effect of wind and Floor Vibration on spatial orientation in VEs.

  • 3DUI - Haptic ChairIO: A system to study the effect of wind and Floor Vibration feedback on spatial orientation in VEs
    2015 IEEE Symposium on 3D User Interfaces (3DUI), 2015
    Co-Authors: Mi Feng, Robert W Lindeman, Hazem Abdel-moati, Jacob C Lindeman
    Abstract:

    In this poster, we present the design, implementation, and evaluation plan of a system called Haptic ChairIO. A design space is first introduced, classifying sensory cues, and describing the potential usage of haptic cues on cognitive tasks in virtual environments (VEs). Then follows the design and implementation of Haptic ChairIO, which is extendable in providing various sensory cue types, consisting of a VR simulation, chair-based motion-control input, and multi-sensory output, including visual, audio, wind, and Floor Vibration feedback. A plan of evaluation has been made to study the effect of wind and Floor Vibration on spatial orientation in VEs.

Jun Chen - One of the best experts on this subject based on the ideXlab platform.

  • universal response spectrum procedure for predicting walking induced Floor Vibration
    Mechanical Systems and Signal Processing, 2016
    Co-Authors: James M. W. Brownjohn, Vitomir Racic, Jun Chen
    Abstract:

    Abstract Floor Vibrations caused by people walking are an important serviceability problem both for human occupants and Vibration-sensitive equipment. Present design methodologies available for prediction of Vibration response due to footfall loading are complex and suffer from division between low and high frequency Floors. In order to simplify the design process and to avoid the problem of Floor classification, this paper presents a methodology for predicting Vibration response metrics due to pedestrian footfalls for any Floor type having natural frequency in the range 1–20 Hz. Using a response spectrum approach, a database of 852 weight-normalised vertical ground reaction force (GRF) time histories recorded for more than 60 individuals walking on an instrumented treadmill was used to calculate response metrics. Chosen metrics were peak values of 1 s peak root-mean-square (RMS) acceleration and peak envelope one-third octave velocities. These were evaluated by weight-normalising the GRFs and applying to unit-mass single degree of freedom oscillators having natural frequencies in the range 1–20 Hz and damping ratios in the range 0.5–5%. Moreover, to account for effect of mode shape and duration of crossing (i.e. duration of dynamic loading), the recorded GRFs were applied for three most typical mode shapes and Floor spans from 5 m to 40 m. The resulting peak values as functions of frequency i.e. spectra are condensed to statistical representations for chosen probability of being exceeded over a wide range of applications. RMS (acceleration) spectra show strong peaks corresponding to the first harmonic of pacing rate followed by clear minima at approximately 3.5 Hz, a second much smaller peak corresponding to the second harmonic and a steady decline with increasing frequency beginning around 5 Hz. One-third octave spectra show asymptotic trends with frequency, span and damping. A comprehensive validation exercise focusing on the acceleration RMS spectra was based on a representative range of Floor samples for which modal properties had been identified and walking response studied during experimental campaigns of Vibration serviceability evaluation. Due to the statistical approach an exact validation would not be possible, hence measured peak RMS values were matched to distributions for the equivalent idealised structure. In the vast majority of cases the measured values, intended to represent worst-case conditions, fitted the upper decile of the corresponding simulated spectra indicating consistency with the proposed approach.

  • Acceleration response spectrum for predicting Floor Vibration due to occupants jumping
    Engineering Structures, 2016
    Co-Authors: Jun Chen, Vitomir Racic
    Abstract:

    Abstract This paper proposes an acceleration response spectrum to predict Floors’ responses due to occupants jumping. Experiments were conducted on individual jumping loads resulting in 506 records. Each record was applied to a single-degree-of-freedom system with various frequencies and damping ratios to obtain a corresponding acceleration response spectrum. Statistical analysis of the results led to a representative spectrum, which is further used to derive an analytical design spectrum curve. The suggested design spectrum covers a structural frequency range of 0.5–15 Hz and consists of three main parts: the first plateau, the second plateau and the descent. Design values for spectrum parameters were determined by fitting each part’s mathematical function to actual data. The proposed spectrum was verified by comparing its predictions with measured responses from an experimental Floor model and Floors of existing structures induced by both single individuals and crowds jumping.