TSUNAMI EFFECTS ON COASTAL STRUCTURES

Jawad Elwir- University of Hawaii at Manoaaelwir@gmail.com (808) 781-9288

Mentors: Dr. Riggs - University of Hawaii at Manoa Dr. Robertson - University of Hawaii at Manoa

8/2/2012

JAWS SUPERCOMPUTER

Outline

• Project description.• Importance of the project. • Model setup. • Results.• Summary. • Acknowledgements.

Project Description

• Impact of a wood log hitting a concrete column in:

a- Longitudinal direction.

b- Transverse direction.

Why This Research Is Important

• Design stronger buildings, bridges, roads, etc.• Save human lives.

Numerical Method

Pole: 19.67 ft long, 0.82 ft diameter Modeled as elastic material

Column: 12.00 ft Long, 0.50 ft diameter. Modeled as rigid material

2.68 mph

Longitudinal Impact Results.

• The force obtained from the f36 kips.

• The duration time

• The force calculated from given equation

kips

• The duration time calculated from given equation:

Transverse Impact

• I performed two mesh convergence studies:

a- Finite element convergence study. b- Time step convergence study.

• Convergence study will enable us to obtain accurate results.

Finite Element Convergence Study Results

• The coarse mesh contained 2100 elements and it gave a force

of 23 kips.

• The fine mesh contained 100,000 element and it gave a force

of 12 kips.

• The time step was 0.001 ms.

Time Step Convergence Study Results

0 0.0002 0.0004 0.0006 0.0008 0.001 0.00120

5

10

15

20

25

Force vs Time

Time(seconds)

Forc

e(ki

ps)

• The coarse mesh gave a force of 12 kips.

• The time step was 0.001 ms.

• The fine mesh gave a force of 22 kips.

• The time step was 1 microsecond.

Discussion Of Transverse Impact Results

• The force obtained from the Convergence studies were 12 kips and 22 kips.

• The duration time = 4ms.

• The force calculated from given equation: = kips.

• The duration time calculated from given equation:

=2.4 ms.

Intended Future Work

• Examine discrepancy between transverse impact results from LS-DYNA and given equations.

• Create a mesh for square concrete column.

Gantt Chart

Summary

• During this summer I worked on modeling a wood pole hitting a concrete column in the longitudinal direction and transverse direction.

• The longitudinal impact results obtained from the model correlate well with given equations.

• The transverse impact results obtained from the model do not correlate well with given equations.

Acknowledgments

• This material is based upon work supported by the National Science Foundation under Grant No 0852082

• Eid Khowitar• Adam McGuire • Matthew Wesley• Evan Greer• H. Ronald Riggs• Ian Robertson• Hawaii Open Supercomputing Center (HOSC)

Sources

• Paczkowski K., Riggs, H.R., Naito C.J, Lehmann. A. one-dimensional model for impact forces resulting from high mass, low velocity debris. Structural Engineering and Mechanics. Vol. 42. No. 6. 2012. Pages 831-847.

• LS-DYNA Theory Manual

• Oliver, s. “Physical properties of common woods ." Wood Properties :

21 Oct. 2009. http://www.csudh.edu/oliver/chemdata/woods.htm  

Questions?