OpenFOAM Modeling of Tsunami Forces on Coastal Structures

Michael Motley Randy LeVeque Frank Gonzalez Marc Eberhad

Xinsheng Qin Andrew Winter Hin Kei Wong

PEER Annual Meeting 28 January 2016

Multi-Scale Modeling of Tsunami Forces

Community-Scale Inundation and Force

Prediction

Structure-Scale Force Prediction

Detailed structural models provide insight into the dynamic fluid forces that a structure may experience to permit

capacity analysis

Computational Fluid Dynamics Modeling

OpenFOAM: Open Field Operation and Manipulation

Purposely developed for solving a wide range of fluid problems Incompressible flows, multiphase flows, buoyancy-driven flows, and

more

Complete CFD software package Comes with 80+ solvers and 170+ utilities

Mesh Generations and Refinements

Data loaders for converting CAD geometries to meshes

Parallelization of fluid problem solutions

In this work, 64-256 processors were commonly used

Other researchers have used up to ~1000 processors

Will be available for use on NHERI Cyberinfrastructure in the coming months

Computational Fluid Dynamics Modeling We convert CAD *.stl files into OpenFOAM 3D Meshes

CAD Rendering OpenFOAM Internal Mesh OpenFOAM Boundary Faces

Computational Fluid Dynamics Modeling We convert CAD *.stl files into OpenFOAM 3D Meshes

CAD Rendering OpenFOAM Internal Mesh OpenFOAM Boundary Faces

Computational Fluid Dynamics Modeling We convert CAD *.stl files into OpenFOAM 3D Meshes

CAD Rendering OpenFOAM Internal Mesh OpenFOAM Boundary Faces

Computational Fluid Dynamics Modeling We convert CAD *.stl files into OpenFOAM 3D Meshes

CAD Rendering OpenFOAM Internal Mesh OpenFOAM Boundary Faces

Experimental Data from Flume Tests

2D 3D

By slightly modifying the geometry of the bridge, we can create scenarios where extrapolating a two-dimensional model does not accurately represent the response of the structure to wave loads.

Consider a skewed bridge:

Modifying the Geometry

Resulting Loading Histories

What about slope effects?

Fluid-air-structure interactions

14.5 15 15.5 16 16.5 17 17.5 18 18.5 19

0

100

200

300

400

500

Time, t (sec)

Ho

rizo

nta

l F

orc

e, F

x (

kN)

Total vs. Component Responses

Fluid-air-structure interactions

Fluid-air-structure interactions

14.5 15 15.5 16 16.5 17 17.5 18 18.5 19-800

-600

-400

-200

0

200

400

600

Time, t (sec)

Ho

rizo

nta

l F

orc

e, F

x (

kN)

Total vs. Component Responses

Structure-Scale Models

14.95 15 15.05 15.1 15.15 15.2 15.25 15.3 15.35

-600

-400

-200

0

200

400

600

Time, t (sec)

Hor

izon

tal

Forc

e, F

x (k

N)

Total vs. Component Responses

Front Faces at 15.25 s Front Bay at 15.35 s

Approximately equal and opposite contributions from back face of girder 1 and front face of girder 2

Structure-Scale Models

15.45 15.5 15.55 15.6 15.65 15.7

-400

-300

-200

-100

0

100

200

300

400

Time, t (sec)

Hor

izon

tal

Forc

e, F

x (k

N)

Total vs. Component Responses

Front Faces at 15.45 sec Bays and Front Barrier at 15.625 s

back face of girder 1 front face of girder 2

Structure-Scale Models

15.45 15.5 15.55 15.6 15.65 15.7

-400

-300

-200

-100

0

100

200

300

400

Time, t (sec)

Hor

izon

tal

Forc

e, F

x (k

N)

Total vs. Component Responses

Front Faces at 15.45 sec Bays and Front Barrier at 15.625 s

back face of girder 2 front face of girder 3

Structure-Scale Models

15 15.5 16 16.5 17 17.5 18 18.5 19

-1500

-1000

-500

0

500

1000

Time, t (sec)

Ver

tical

For

ce, F

y (k

N)

Total vs. Component Responses

Structure-Scale Models

15 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8

0

200

400

600

800

1000

1200

Time, t (sec)

Ver

tical

For

ce, F

y (k

N)

Total vs. Component Responses

Deck Impact at 15.25 s Internal Deck Impact at 15.65 s

Largest peaks occur on deck bottom and coincide with equal and opposite spikes in horizontal load, implying air effects, as do many of the minor peaks

OpenSees/OpenFOAM Model Overview

OpenSees/OpenFOAM Model Overview

OpenSees/OpenFOAM Model Overview

Earthquake/Tsunami Response