Earthquake Simulation Table SDI – Team 02 May 3, 2014

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

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

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.

Shake Tables

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

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

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

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

P-Wave

S-Wave

Love Wave

Rayleigh Wave

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

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

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

Shear Wave Particle Dislocation

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

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

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

Frequency vs. FFT Amplitude

Revised Design

Final Design

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

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”

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

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

References (2006). Retrieved 2014, from UPSeis: http://www.geo.mtu.edu/UPSeis/waves.html 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), 503-538. doi:http://dx.doi.org.libproxy.temple.edu/10.1016/0169- 2070(95)00621-4

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Questions? https://sites.google.com/a/temple.edu/earth-shaker/home