1. Earthquake Simulation Table
SDI – Team 02
May 3, 2014

2. Group Members Tyler Williams, CE Competition Analyst, Researcher
Paulina Olmedo, CE
Team Leader, Webmaster, Earthquake Researcher
Faculty Advisor
Dr. Joseph Coe
Philip Longo, ME
Simulation/Prototype Design, SolidWorks
Ilir Marku, CE
Earthquake Analyst, Researcher

3. Preview Design Constraints Seismic Waves Preliminary Design
Analysis of parameters
Revised Design/ Budget

4. Abstract
The purpose of our project is to design an earthquake shake table to be used by the Temple University Civil and Environmental engineering program for educational purposes and by students that wish to enter the annual EERI seismic design competition. It will have one-dimensional motion, replicating earthquake ground motions. The final goal is for the shake table to replicate an actual earthquake motion that students can test a simple structures on. In order to achieve this we need to acquire actuators and accelerometers to create and record both the motion of the table itself, and the simple structure to be tested. Using the accelerometers, we will be able to solve for the forces that the simulated earthquake motion exerts on the simple structure. This will allow future students to test the structural stability of their designs on a shake table with similar design specifications as the EERI seismic design competition.

5. Shake Tables

6. Functional Design Constraints
Name
Description
Peak Acceleration
The table will achieve a peak acceleration of 1.5 g’s
Design Payload
The table will be able to support and successfully test structures up to 11 kg
Operation Frequency
The shake table will operate at a relative frequency of 1 Hz
Peak Velocity
The peak velocity of the shake table will be 30 cm/sec
Stroke Distance
The shake table will have a stroke distance of 15 cm

7. Non - Functional Design Constraints
Type
Name
Description
Economic
Cost
Less than $500
Performance
Power
DC motor input
Sustainability
Reliability
Factor of safety > 2.0
Portability
Size
Table Area:18.0 x18.0 inches
Documentation
Data Collection
LabView
MatLab

8. Determine Wave Parameters Collected Earthquake Records
Project Overview
Shake Table &
Earthquake
Research
Seismic Wave Research
Determine Wave Parameters
Collected Earthquake Records
Shake Table V.3 Design

9. Wave Motions Body Waves Surface Waves P - Wave S - Wave Love Wave
Rayleigh Wave

10. P-Wave

11. S-Wave

12. Love Wave

13. Rayleigh Wave

14. Wave Selection Body Waves vs. Surface Waves
We cant replicate body or surface waves
We plan to mimic a shearing motion at the surface

15. Shake Table I.0
The design can only mimic a shear wave once it reaches the surface of the earth
Rayleigh and Love Waves are much to complex to mimic even for the most intricate shake tables
2 degrees of motion- too complex, too expensive

16. Shear Wave
Shear waves disrupt the Earths crust by slicing it laterally

17. Shear Wave Particle Dislocation

18. Table Wave Properties G Force 1.5 (m/s^2) Acceleration 14.715(m/s^2)
Frequency 1(Hz)
Stroke Amplitude 7.5(cm)

19. Frequency vs. Amplitude
All seismic waves that travel through a medium have a specific amplitude and frequency
The Frequency (1/T) of a surface wave determines the speed at which it propagates
The amplitude of a wave determines the amount of displacement between the equilibrium point and the peak of a wave
The amplitude is what actually causes the damage during an earthquake as it literally displaces the ground

20. FFT - Analysis
The Fast Fourier Transform (FFT) allows one to analyze data for relative importance
For our purposes, it allowed us to take real world acceleration vs. time data from various earthquakes and plot the frequency vs. amplitude
This gave us the ability to see at which frequencies an earthquake’s amplitude would be the highest
Modeling a wide range of earthquakes allowed us to determine the frequency at which the peak amplitude most often occurs

21. Frequency vs. FFT Amplitude

22. Revised Design

23. Final Design

24. Drive System Design Circular motion is outputted as linear motion
Using a circular disk allowed our team to visualize the displacement our shake table would create
Using a circular plate also made frequency calculations, in comparison to motor specs much easier

25. Materials List Part Name Specifcs Motor 12v DC at 2.4 rpm Bearings
2 at ½” Diameter
Aluminum Rails
Aluminum Rail Stands
2 at Legth, Height, Width
Motor Mount
See Final Design
Crank arm
See Final Desing
Top Plate
20in. x 20in. Area
Base Plate
24” x 24”

26. Budget Part Amount Price Motor 1 $44.30 Top Plate $4.86 Base Plate
$193.52
Rail Bearing 2
$94.4
Aluminum Rail
$128.96
Rail Stand
$3.62
Crank Wheel
$25.86
Motor Mount
$0.4
Crank Arm
$0.1
Total
$494.06

27. SDII-Schedule Assemble the Shake Table Write Code using LabView
Undergo Testing
Adjust Parts as necessary
Finish Shake Table

28. References
(2006). Retrieved 2014, from UPSeis:
Lam, Nelson. Wilson, John. Chandler, Adrian. Hutchinson, Graham. (2000) Response spectral relationships for rock sites derived from the component attenuation model. Earthquake Engineering And Structural Dynamics Earthquake Engng Struct. Dyn. 2000; 29:1457}1489
Vere-Jones, D. (1995). Forecasting earthquakes and earthquake risk. International Journal of Forecasting, 11(4), doi: 2070(95)

29. Bring Your Child to Work Day

30. Questions?