Forced-Vibration Tests of the Daniel-Johnson Multiple-Arch Dam

2017 ◽  
pp. 397-408
Author(s):  
O. Gauron ◽  
Y. Boivin ◽  
S. Ambroise ◽  
P. Paultre ◽  
J. Proulx ◽  
...  
Keyword(s):  
Forced Vibration ◽  
Arch Dam ◽  
Vibration Tests

Forced-Vibration Tests and Numerical Modeling of the Daniel-Johnson Multiple-Arch Dam

2018 ◽  
Vol 32 (2) ◽  
pp. 04017137 ◽  
Author(s):  
Olivier Gauron ◽  
Yannick Boivin ◽  
Steeve Ambroise ◽  
Adamou Saidou Sanda ◽  
Carl Bernier ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Forced Vibration ◽  
Arch Dam ◽  
Vibration Tests

scholarly journals Ambient Vibration Tests of an Arch Dam with Different Reservoir Water Levels: Experimental Results and Comparison with Finite Element Modelling

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Sergio Vincenzo Calcina ◽  
Laura Eltrudis ◽  
Luca Piroddi ◽  
Gaetano Ranieri
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Water Levels ◽  
Arch Dam ◽  
Experimental Results ◽  
Ambient Vibration ◽  
Reservoir Water ◽  
Ambient Vibration Tests ◽  
Vibration Properties ◽  
Vibration Tests

This paper deals with the ambient vibration tests performed in an arch dam in two different working conditions in order to assess the effect produced by two different reservoir water levels on the structural vibration properties. The study consists of an experimental part and a numerical part. The experimental tests were carried out in two different periods of the year, at the beginning of autumn (October 2012) and at the end of winter (March 2013), respectively. The measurements were performed using a fast technique based on asynchronous records of microtremor time-series. In-contact single-station measurements were done by means of one single high resolution triaxial tromometer and two low-frequency seismometers, placed in different points of the structure. The Standard Spectral Ratio method has been used to evaluate the natural frequencies of vibration of the structure. A 3D finite element model of the arch dam-reservoir-foundation system has been developed to verify analytically determined vibration properties, such as natural frequencies and mode shapes, and their changes linked to water level with the experimental results.

FORCED VIBRATION TESTS AND THEORETICAL STUDIES ON DAMS.

1980 ◽  
Vol 69 (3) ◽  
pp. 605-634 ◽  
Author(s):  
RT SEVERN ◽  
AP JEARY ◽  
BR ELLIS ◽  
Keyword(s):  
Forced Vibration ◽  
Theoretical Studies ◽  
Vibration Tests

The Lift Force on a Cylinder Vibrating in a Current

1990 ◽  
Vol 112 (4) ◽  
pp. 297-303 ◽  
Author(s):  
G. Moe ◽  
Z.-J. Wu
Keyword(s):  
Free Vibration ◽  
Forced Vibration ◽  
Cross Flow ◽  
Reference Frequency ◽  
Average Force ◽  
Vibrational Response ◽  
Uniform Current ◽  
Extensive Program ◽  
Vibration Tests ◽  
Lock In

This paper reports an extensive program of forced and free vibration tests on a single circular cylinder moving mainly perpendicularly to a uniform current. For both free and forced vibration tests, two cases were investigated: one in which the cylinder was restrained in the in-line direction and the other in which it was supported on suitable springs. The cross-flow vibrational response and hydrodynamic forces on the cylinder were measured. Large variations of motion frequency in the “lock-in” range were found from the free vibration tests. This leads to two different definitions of reduced velocity, namely, a so-called nominal reduced velocity based on one reference frequency and the true reduced velocity based on the actual vibration frequency. When different results are compared, the true reduced velocity should be used. The forced vibration tests showed, as may be expected, that the transverse force in the “lock-in” range on the average will add energy to the cylinder at moderate motion amplitudes and subtract energy at large amplitudes. Some conditions resulting in a steady-state vibration of a flexibly mounted cylinder were analyzed. The actual force traces also show very large and apparently random deviations from the average force amplitude. The results from the forced and the free vibration tests are consistent with each other if the true reduced velocity and reduced amplitude are the same.

Electromechanical Coupling of PZT Nanofibers

2008 ◽  
Author(s):  
Shiyou Xu ◽  
Yong Shi
Keyword(s):  
Forced Vibration ◽  
Output Voltage ◽  
Electromechanical Coupling ◽  
Mechanical Strain ◽  
Electrospinning Process ◽  
Piezoelectric Response ◽  
Vibration Source ◽  
Titanium Film ◽  
Three Point Bending ◽  
Vibration Tests

This paper presented the results of electromechanical characterization of PZT nanofibers through applied mechanical strain and forced vibration. PZT nanofibers were fabricated by electrospinning process. Titanium film with ZrO2 layer was used to collect the nanofibers and also used as the substrates of the test coupons for the bending tests. Mechanical strain was applied to the test coupons through three-point-bending using Dynamic Mechanical Analyzer (DMA). The largest output voltage was 170mV under 0.5% applied strain. Silicon substrate with trenches was also used to collect the PZT nanofibers for the forced vibration tests. The output voltage from 150Hz sinusoid vibration source was also measured. The peaks of the output voltage were 64.9mV and −95.9mV, respectively. These tests have demonstrated the piezoelectric response of PZT nanofibers. Further tests are to be conducted to precisely determine the piezoelectric constants of PZT nanofibers.

Forced Vibration Tests for In-Line Vortex-Induced Vibration to Assess Partially Strake-Covered Pipeline Spans

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Jie Wu ◽  
Decao Yin ◽  
Elizabeth Passano ◽  
Halvor Lie ◽  
Ralf Peek ◽  
...  
Keyword(s):  
Forced Vibration ◽  
Hydrodynamic Force ◽  
Cross Flow ◽  
Added Mass ◽  
Vortex Induced Vibrations ◽  
Helical Strakes ◽  
Vibration Tests ◽  
Flow Vortex ◽  
Hydrodynamic Data ◽  
Mass Functions

Abstract Helical strakes can suppress vortex-induced vibrations (VIVs) in pipelines spans and risers. Pure in-line (IL) VIV is more of a concern for pipelines than for risers. To make it possible to assess the effectiveness of partial strake coverage for this case, an important gap in the hydrodynamic data for strakes is filled by the reported IL forced-vibration tests. Therein, a strake-covered rigid cylinder undergoes harmonic purely IL motion while subject to a uniform “flow” created by towing the test rig along SINTEF Ocean's towing tank. These tests cover a range of frequencies, and amplitudes of the harmonic motion to generate added-mass and excitation functions are derived from the in-phase and 90 deg out-of-phase components of the hydrodynamic force on the pipe, respectively. Using these excitation- and added-mass functions in VIVANA together with those from experiments on bare pipe by Aronsen (2007 “An Experimental Investigation of In-Line and Combined In-Line and Cross-Flow Vortex Induced Vibrations,” Ph.D. thesis, Norwegian University of Science and Technology, Trondheim, Norway.), the IL VIV response of partially strake-covered pipeline spans is calculated. It is found that as little as 10% strake coverage at the optimal location effectively suppresses pure IL VIV.

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