Component Test Results: Record Number 57

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Citation

TitlePre-Qualification Testing of Viscous Dampers for the Golden Gate Bridge Seismic Rehabilitation Project
AuthorsAiken, Ian D.; Kelly, James M.
PublicationEarthquake Engineering Research Center Report No. EERC-STI/95-04
ObjectivesEvaluate the performance of a FIP/Energy Absorption Systems viscous damper under a range of loading temperatures and displacement conditions.
AbstractThis report presents the results of the testing of a viscous damping device provided by FIP/Energy Absorption Systems to the Earthquake Engineering Research Center (EERC) of the University of California at Berkeley for the pre-qualification testing as a part of the seismic rehabilitation of the Golden Gate Bridge. In all, four different viscous dampers from four different manufacturers were tested in the pre-qualification program. The test dampers were of a reduced size with respect to the full-scale dampers that will ultimately be used in the retrofit of the bridge. The reduced damper size permitted a comprehensive dynamic test program to be undertaken utilizing an existing test facility. The test dampers were required to have a displacement capability of +/-152mm(6in) and produce a force of 445kN(100 kips) under a maximum test velocity of 50cm/s(20in/s). With respect to the full-scale dampers, these parameters correspond to scale factors of 1:6.5 for force, 1:4 for displacement, and 1:3.75 for velocity. The primary goals of the test program were to: evaluate the constitutive relationships of the dampers; evaluate the energy dissipation of the dampers; evaluate wear characteristics of the dampers' sealing systems; and subject the dampers to a Maximum Credible Displacement loading. The tests were performed at ambient temperatures of 40deg.F, 70 deg.F, and 125 deg.F. Most of the tests performed consisted of multiple-cycle constant-velocity displacement loadings at a range of amplitudes and frequencies. Sinusoidal displacement tests were also used to evaluate the energy dissipation capacity of the dampers.

Component Details: Viscous Damper

Manufacturer FIP/Energy Absorption Systems
Design damping force 463kN
Velocity exponent 0.1
Damping constant 13.5kN-sec/mm
Displacement capacity(stroke) +/-155mm
Scale factor 0.25 (displacement)
Rod type Double-ended
Accumulator/reservoir External

Test Details

Displacement range mm 15.225.476.2152.4
Loading frequency Hz 50.0167
Loading type SinusoidalEndurance/WearEarthquake inputConstant-velocity
Test temperature degrees C 254075
Velocity range mm/sec 12725438150825.450.8

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