Characterization of hydrodynamic properties from free vibration tests of a large-scale bridge model
Section snippets
Introduction and background
Hurricanes in 2004 (Ivan) and 2005 (Katrina) caused failure of many existing coastal highway bridges (Bradner et al., 2010, Cuomo et al., 2007). Bridge structures are the critical lifeline components of an infrastructure network, enabling disaster response and recovery. Therefore, ensuring satisfactory performance increases community resilience and minimizes both human and economic losses. The observed bridge failures spurred research to better understand wave forces on bridges and
Motivation and significance
As described in the previous section, most experimental tests and numerical models are of rigidly supported bridge structure models, that do not properly reflect realistic structural stiffness (Bradner et al., 2010, Istrati, 2017). As presented in Istrati (2017) and Schumacher et al. (2008), dynamic structural properties have an important effect on the measured forces. Except for the two large-scale experimental tests performed by Bradner et al. (2010) and Istrati (2017), substructure
Experimental test setup and description of tests
The experimental test setup used for this study is illustrated in Fig. 1. The setup was designed to study the structural response of highway bridge superstructures under hurricane wave action and is fully described in Bradner et al. (2010). In this article, we focus on the free vibration response of the model (without wave action) to characterize the dynamic properties of the model. A unique aspect of the setup is that the horizontal support flexibility was adjusted to represent different
Initial observations from free vibration tests
The bridge model in this setup can be represented as a single degree of freedom (SDF) mass–spring–damper system. In order to arrive at an equation of motion that accurately represents the physical model, the dynamic properties, including mass, stiffness, and damping, were characterized using the free vibration test results.
The time history responses of all free vibration tests (see Table 1) were visualized in the time domain and analyzed in the frequency domain by means of the discrete Fourier
Analysis
In this section, the equation of motion (EOM) that best describes the free vibration response of the bridge superstructure model under varying levels of water submersion is developed, a suitable numerical scheme to solve it is presented, and an optimization scheme to estimate the dynamic properties for the system using the empirical results are discussed. Additional details regarding the development and evaluation of the numerical scheme as well as the optimization scheme are presented in
Investigation of added mass parameters
This section investigates the added mass derived from results of the complex shaped bridge model. Added mass is represented by and only the full-depth submersion case, d* 1, is considered here. Following the work presented in Chandrasekaran et al. (1972), the first quantity to be introduced is the added mass factor, , which is the ratio between added mass, and dry mass (measured mass in air), , it is computed as where and are the natural vibration
Summary and conclusions
In this paper, the free vibration response of a large-scale highway bridge superstructure model under varying levels of water submersion was investigated. The objective of the study was to characterize the salient dynamic properties required for the numerical modeling of bridge fluid–structure interaction problems. In addition to varying water levels, the substructure flexibility in the experimental test setup was varied by employing two sets of springs having different stiffnesses. To capture
Notations and Abbreviations
c: viscous damping coefficient of the SDF system
d*: non-dimensional parameter, represents the SWL relative to the girder soffit line
EOM: equation of motion
F: friction force
: natural frequency of the structure in air
: natural vibration frequency
: natural frequency of the structure in water, d* 1.
k: stiffness coefficient of the SDF system
m: mass of the SDF system
: added (or virtual) mass
: dry mass (or mass vibrating in air) of the SDF system
: reference fluid mass
Phase 2a:
CRediT authorship contribution statement
Thomas Schumacher: Conception and design of study, Acquisition of data, Analysis and/or interpretation of data, Drafting the manuscript, Revising the manuscript critically for important intellectual content. Alaa W. Hameed: Conception and design of study, Analysis and/or interpretation of data, Drafting the manuscript, Revising the manuscript critically for important intellectual content. Christopher Higgins: Conception and design of study, Acquisition of data, Analysis and/or interpretation of
Declaration of Competing Interest
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: A financial support was provided by The Higher Committee of Education Development (HCED) of Iraq for Alaa W. Hameed’s to study at Portland State University.
Acknowledgments
The authors would especially like to thank Professor Harry Yeh of Oregon State University for his thoughtful advice and suggestions for interpretation and application of the experimental results. The second author would like to acknowledge the financial support provided by The Higher Committee of Education Development (HCED) in Iraq for her studies at Portland State University. The experimental work that produced the data set analyzed in this study was partially supported by the US Department
References (40)
- et al.
Wave-in-deck loads on exposed jetties
Coast. Eng.
(2007) - et al.
A decrement method for the simultaneous estimation of Coulomb and viscous friction
J. Sound Vib.
(1996) - et al.
Experiments and computations of solitary-wave forces on a coastal-bridge deck. Part II: Deck with girders
Coast. Eng.
(2014) - et al.
Computation of wave loads on the superstructures of coastal highway bridges
Ocean Eng.
(2011) Identifying Coulomb and viscous damping from free-vibration acceleration decrements
J. Sound Vib.
(2005)- et al.
Experiments and computations of solitary-wave forces on a coastal-bridge deck. Part I: Flat plate
Coast. Eng.
(2014) - et al.
Numerical simulations of lateral restraining stiffness effect on bridge deck–wave interaction under solitary waves
Eng. Struct.
(2015) - et al.
Numerical investigation of the lateral restraining stiffness effect on the bridge deck-wave interaction under Stokes waves
Eng. Struct.
(2017) Development of the AASHTO Guide Specifications for Bridges Vulnerable to Coastal Storms
(2008)Large-Scale Laboratory Observations of Wave Forces on a Highway Bridge Superstructure
(2008)
Experimental setup for a large-scale bridge superstructure model subjected to waves
J. Waterw. Port Coast. Ocean Eng.
Virtual mass of submerged structures
J. Hydraul. Div.
Hydrodynamic investigation of coastal bridge collapse during Hurricane Katrina
J. Hydraul. Eng.
Numerical modeling of wave forces on movable bridge decks
J. Bridge Eng.
Two-frequency oscillation with combined Coulomb and viscous frictions
J. Vib. Acoust.
LXXIII. Forced vibrations with combined viscous and coulomb damping
Lond. Edinb. Dublin Philos. Mag. J. Sci.
Effective Mass and Damping of Submerged Structures
Wave Forces on Bridge Decks Draft Report
An Introduction to Numerical Methods and Analysis
An efficient numerical method for earthquake cycles in heterogeneous media: Alternating subbasin and surface-rupturing events on faults crossing a sedimentary basin
J. Geophys. Res. Solid Earth
Cited by (4)
Water–structure interaction analysis of a segmental bridge using ambient vibration testing at different water levels
2023, Journal of Civil Structural Health MonitoringDigital Filter Design for Force Signals from Eulerian–Lagrangian Analyses of Wave Impact on Bridges
2022, Journal of Marine Science and EngineeringA 2D MODEL USING PFEM FOR A BRIDGE SUPERSTRUCTURE SUBJECTED TO WAVE ACTION
2022, International Middle Eastern Simulation and Modelling Conference 2022, MESM 2022