1. Shake Tables Derek Jacobs & Julia Johnson

2. What is a shake table? Used to replicate earthquakes Can also used for noise & vibration tests Their most basic form, shake tables consist of a flat plate that moves by computer control Shake tables come in a large variety of sizes and capabilities

3. Performance Features Shake tables can have many different features –Degrees of freedom –Capacity (weight of structure that can be supported) –Frequency range –Stroke range –Velocity range

4. How do they work? Table Hardware –System of pistons & motors under the plate –May or may not be sensors in the table itself Control Hardware & Software –System of connections that transfer commands from a computer to the table –One of many types of software programs chosen for a given table

5. Shake tables from around the world University of California San Diego Large high performance shake table Enables large scale experiments to be performed –Full scale buildings –Single and multiple column bridge bents –Life line structures –Nuclear containment casks –Seismic isolation systems

6. Shake tables from around the world University of California San Diego Properties –Single DOF w/ capability of upgrading to six DOF –Capacity: Horizontal force: 6.8MN Overturning Moment: 50MN-m Vertical Payload: 20MN –Frequency range: 0-20Hz –Stroke range: ± 0.75m –Velocity range: ±1.8m/s

7. Shake tables from around the world Rensselaer Polytechnic Institute 2-D shake table Provides periodic or random shaking determined by input signal Used in conjunction with centrifuge Can facilitate the investigation into the response of scale geotechnical or soil structure systems

8. Shake tables from around the world Rensselaer Polytechnic Institute Properties –965mm x 660mm –2 DOF –Capacity: 50 kN –Frequency range: 0-350 Hz –Stroke: 6.35mm –Velocity Range: ±1.1m/s –Centrifugal acceleration max: 100g

9. Shake tables from around the world State University of New York -Buffalo Dual-movable tables –Used for real time testing of structures up to 120 long and 30 high –Tables can be used fully in-phase or totally unrelated –Can test large variety of scale structures from buildings to road segments

10. Shake tables from around the world State University of New York -Buffalo Properties –Size: 3.6m x 3.6m –6 DOF –Capacity: Vertical payload: 50 tons each Overturning moment: 46ton-meter –Frequency range: 1-50Hz –Stroke: ±150m, ±150m, ±75m –Velocity Max: 1.25m/s, 1.25m/s, 0.5m/s –Acceleration Max: ±1.15g w/ 20 ton specimen

11. Shake tables from around the world Miki City, Japan Worlds largest shake table Offers a wide variety of testing capabilities: –RC structures –Soil pile-structure –Wooden Structures Part of the E-Defense 5 actuators in each horizontal axis and 14 in the vertical axis

12. Shake tables from around the world Miki City, Japan Properties –20m x 15m –3 DOF –Capacity: Payload: 12 MN Overturning moment: 150 MN-m –Stroke: ±100cm Horiz. ±50cm Vert. –Velocity ±200cm/s Horiz. ±70cm/s Vert. –Acceleration ±900cm/s 2 Horiz. ±1,500cm/s 2 Vert.

13. Shake tables from around the world University of Nevada Reno Biaxial multiple shake table facility 3 identical biaxial shake tables Used for research on long, specially distributable structural and geotechnical systems

14. Shake tables from around the world University of California Berkley First of its kind Properties –20ft x 20ft –3 DOF –Capacity: 100kip –Acceleration Range: ±1.5g –Stroke: 10.5 ft, 8.66 ft

15. References http://nees.buffalo.edu http://nees.unr.edu http://nees.rpi.edu http://nees.org http://www.bosai.go.jp/hyogo/ Make Your Own! –http://www.exo.net/~donr/activities/Shake_Table. pdfhttp://www.exo.net/~donr/activities/Shake_Table. pdf