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212 Ketter Hall, North Campus, Buffalo, NY 14260 www.civil.buffalo.edu

Fax: 716 645 3733 Tel: 716 645 2114 x 2400

Control of Structural VibrationsLecture #3

Instructor:

Andrei M. Reinhorn P.Eng. D.Sc.Professor of Structural Engineering

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Response of Structure with Damping Devices

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Fluid Damper

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Force Displacement of Structural System

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Spectra for Highly Damped Systems

MODIFICATION OF RESPONSE SPECTRA FOR HIGH DAMPING

•aMAX = Sa = PSEUDO-ACCELERATION

•aMAX = (f1+2f2) Sa ( f1=cos[tan-1(2)] ; f2-=sin[tan-1(2)] )

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Spectra for Highly Damped Systems

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Spectra for Highly Damped Systems

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Spectra for Highly Damped Systems

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Structural Influence of Damper

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Structural Influence of Damper

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Structural Influence of Damper

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Structural Influence of Damper

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Influence of Construction System

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Influence of Construction System

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Modification of effective properties

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Modification of effective properties

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Energy Dissipation Devices

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Viscoelastic Dampers

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Fluid Damper

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Viscous and Viscoelastic Devices -

Behaviour

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Metalic Damper

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Friction Damper

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Hysteretic Damping Devices

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Additional Viscoelastic Dampers

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Additional Viscoelastic Dampers

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Additional Friction Dampers

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Additional Friction Dampers

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Additional Hysteretic Dampers

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Additional Hysteretic Dampers

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Comparison of Devices

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Comparison of Devices

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Comparison of Construction Efficency

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Example

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Example

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Equivalent Elastic Damped Systems

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Equivalent Elastic Damped Systems

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Equivalent Elastic Damped Systems

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Equivalent Elastic Damped Systems

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Capacity (Curve) of StructureCapacity is a function, not a single value, indicating the strength of the system at a deformed position of the structure

ElasticRange

MechanismRange

e

PartialFractureRange

CompleteCollapse

ProgressiveYieldingRange

EffectiveStructureYieldPoint

EffectiveStructureYieldStrength

EffectiveStructureYieldDisplacement DEFORMATION

STRE

NGTH

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Yielding System

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