The Carleton Laboratory maintains a medium-scale shake table facility to conduct experimentation in structural dynamics and particularly how to monitor and actively control structures subjected to earthquake ground motions or other force excitations. The table, which was custom designed by ANCO Engineers for the Department, is capable of carrying a maximum 3-ton payload on the 5ft x 5ft table, and is capable of shaking a 2-ton payload with 3 g acceleration (i.e. three times the acceleration of gravity in the horizontal direction). The shake table is ideally suited to seismic applications, because the hydraulic actuator can produce a stroke of +/- 5 inches (10 inch total stroke). The actuator has a 3-stage servo-valve controlled by an analog inner-loop control system (displacement based), and a digital outer-loop control system (acceleration feedback based).
SUMMARY OF KEY FEATURES
- Uniaxial horizontal motion
- 5 ft by 5 ft (1.5 m by 1.5 m) steel table
- Dual roller- rail bearings to guide table
- Peak-to-peak displacement of 10 inches double amplitude
- Peak velocity of 60 in/sec (1.5 m/s)
- Peak acceleration (with 2-ton test specimen) of 3.0g
- Maximum test specimen weight of 2 tons
- Frequency range 0-100Hz (design) (Note: actual performance exceeds this spec.)
Data Acquisition System
The current data acquisition system includes the Data Physics digital controller, Microstar Labs and National Instruments data acquisition cards. Most of the data pre- and post-processing is performed in MATLAB on 2 dedicated computers which are also network accessible.
For further information contact Andrew Smyth at +1.212.854.3369.
Data Acquisition and Table Control Computers
Close-up of 22-kip Actuator & 3-Stage Servovalve