• Structural Engineering and Mechanics
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• v.82 no.3
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• pp.283-294
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• 2022

An inerter is a passive mechanical element whose inertance can be thousands of times its own physical mass. This paper discusses the application of an inerter-based passive control system, termed rotational inertial double-tuned mass damper (RIDTMD), to mitigate human-induced floor vibrations. First, the acceleration frequency response function of the floor with an RIDTMD is first derived. It is then employed to determine the optimal design parameters of the RIDTMD using the extended fixed-points technique. Based on a theoretical analysis, design-oriented empirical functions are proposed for the RIDTMD optimal parameters, whose performance for floor vibration control is evaluated by numerical examples, in which three typical human-induced load types are considered: walking, jumping, and bouncing. The results indicate that the applicability and effectiveness of the RIDTMD for human-induced floor vibration control are robust for various load types, load frequencies, and floor natural frequencies. For the same mass ratio, the RIDTMD is better than the TMD in reducing the floor vibration amplitude and improving the effective frequency suppression bandwidth, and for the same vibration suppression effect, the mass of the RIDTMD is much lighter than that of the TMD.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.9
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• pp.731-740
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• 2014

Occupants induced floor vertical vibrations may cause other occupant's annoyance and lead to social loss. To help control such floor vibrations, several criteria have been developed mostly based on human perception tests and floor vibration tests. Floor vibration is evaluated by comparison with criteria and vibration parameters of subject floor, such as frequency, damping ratio, acceleration value, vibration duration time and occurrence frequency. Three acceleration value parameters are used in criteria; peak acceleration, rms acceleration and VDV, when a floor vibration serviceability is evaluated. Meanwhile rms acceleration and peak acceleration are adopted as vibration limit value in criteria and researches of human perception for vibration. Occupants induced floor vibration is transient rather than steady state. However, rms acceleration is not reliable parameter for evaluating transient vibration. The objective of this study is to investigate the characters of human perception level according to acceleration value parameters for vibration induced by heel impacts and walking activities.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.3
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• pp.186-193
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• 2003

Floor vibrations in residence and office buildings are typically induced by heel drop and walking movement of occupants. The criteria of most vibration provisions have been developed based on the vibration caused by heel drop impact rather than walking. There may be considerable differences between the vibration characteristics induced by walking and heel drop. The effect of walking vibration was not well reflected on current provisions. In this paper, shaking table test was performed to investigate the human perception level against the vibrations due to walking and heel drop. This study attempts to compare the human Perception level of two different vibration sources. Also, this study investigates the effect of damping on a Perception level under heel drop and walking vibration.

• Wind and Structures
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• v.9 no.5
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• pp.345-356
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• 2006

It is well known that cylinder steel stacks are heavily impacted by vortex-induced vibration. However, the wind-induced vibration behaviors of tower-supported steel stacks are not clarified due to a lack of observation. We studied a stack's response to strong winds over a long period of time by observing the extreme wind-induced vibration of a 200 m-high tower-supported steel stack. This experiment aimed to identify the wind-induced vibration properties of a tower-supported steel stack and assess the validity of the vibration control method used in the experiment. Results revealed a trend in wind-induced vibration behavior. In turn, an effective measure for controlling such vibration was defined by means of increasing the structural damping ratio due to the effects of the tuned mass damper to dramatically decrease the vortex-induced vibration of the stack.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.5-13
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• 2017

Noise complaints among neighbors in apartment building are mainly caused by floor impact noise that is structure born noise due to occupant induced floor vibration. To control this noise problems many researchers have investigated floor systems and finishing materials. Light-weight impact noise affects by finishing materials, but heavy-weight impact noise induced by heel impacts during normal walking or jumping of children is concerned with structural system and floor vibration. To figure out the characteristics of floor impact noise and transmission of floor vibration due to human activities, vibration tests were conducted in apartment buildings. Impact hammer, heel drop and walking activities were loaded at center of upstairs living room, and accelerations of slabs for both upstairs and downstairs and sound pressure levels for downstairs were measured. The acceleration ratio of transmitted floor vibration to downstairs and human induced vibration in upstairs was between 0.5 and 1.0 according to slab size, wall, and load type. And floor impact noise occurred in the range of natural frequency of slab.

• Structural Engineering and Mechanics
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• v.43 no.5
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• pp.607-621
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• 2012

The Expo Culture Centre is one of the permanent buildings at the World Expo 2010 in Shanghai, China. The main structure has an oval shape and consists of 36 radial cantilever steel trusses with different lengths and inner frames made of concrete-filled rectangular steel tube members. Tuned mass dampers are used to reduce the excessive vibrations of the sixth floor that are caused by human-induced resonance. A three-dimensional analytical model of the system is developed, and its main characteristics are established. A series of field tests are performed on the structure, and the test results show that the vertical vibration frequencies of most structural cantilevers are between 2.5 Hz and 3.5 Hz, which falls in the range of human-induced vibration. Twelve pairs of tuned mass dampers weighing 115 tons total were installed in the structure to suppress the vibration response of the system. These mass dampers were tuned to the vertical vibration frequency of the structure, which had the highest possibility of excitation. Test data obtained after the installation of the tuned mass dampers are used to evaluate their effectiveness for the reduction of the vibration acceleration. An analytical model of the structure is calibrated according to the measured dynamic characteristics. An analysis of the modified model is performed and the results show that when people walk normally, the structural vibration was low and the tuned mass dampers have no effect, but when people run at the structural vibration frequency, the tuned mass dampers can reduce the floor vibration acceleration by approximately 15%.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.347-362
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• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

• Smart Structures and Systems
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• v.20 no.5
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• pp.525-537
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• 2017

This paper explores different vibration control strategies for the cancellation of human-induced vibration on a structure with time-varying modal parameters. The main motivation of this study is a lively urban stress-ribbon footbridge (Pedro $G\acute{o}mez$ Bosque, Valladolid, Spain) that, after a whole-year monitoring, several natural frequencies within the band of interest (normal paring frequency range) have been tracked. The most perceptible vibration mode of the structure at approximately 1.8 Hz changes up to 20%. In order to find a solution for this real case, this paper takes the annual modal parameter estimates (approx. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the most-repeated modal properties of the aforementioned mode, b) two semi-active TMD strategies, one with an on-off control law for the TMD damping, and other with frequency and damping tuned by updating the damper force. All strategies have been carefully compared considering two structure models: a) only the aforementioned mode and b) all the other tracked modes. The results have been compared considering human-induced vibrations and have helped the authors on making a decision of the most advisable strategy to be practically implemented.

• Progress in Medical Physics
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• v.5 no.2
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• pp.77-85
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• 1994

In this paper, the vibration response characteristics of individual's subjective are studied to whole-body and hand-arm induced vibration. For defining limits of vibration exposure to human, experimental data are investigated in a set of vibration criteria specified in ISO Standard 2631. Instrumentation requirements for evaluation of the responses of humans to vibration according to these criteria are discribed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.159-166
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• 2000

Structures with a long span have a higher possibility of experiencing excessive vibration induced by human activities such as walking, running, jumping and dancing. These excessive vibration give occupants annoyance. The general method for the vibration analysis of structures subjected to walking loads is to apply a series of nodal loads with assigned time delays at the nodes. But this method has a limit in representing the walking loads. In this study, the equivalent nodal loads are introduced for an effective analysis of floor vibration induced by walking loads. And, walking loads with difference walking rate are measured and applied to the analytical model for numerical analysis.