Shaking Table

The Laboratory is equipped with a state-of-the-art shaking table (designed and constructed by ANCO Engineers), which is capable of shaking soil-structure specimens of up to 2 tons at accelerations of up to 1.6 g on its 1.3 m x 1.3 m table. The shaking table can reproduce any ground motion, from synthetic motions to real earthquake records. The hydraulic actuator is capable of producing a stroke of +/- 75 mm. The seismic motion can be applied to all three directions (x , y, and z). The actuators have a servo-valve controlled by an analog inner-loop control system (displacement based), and a digital outer-loop control system (acceleration feedback based).

Dimensions : 1.3 m x 1.3 m table with a grid of holes 20 cm x 20 cm (Μ14) in order to fix the specimens on the seismic table
Degrees of Freedom : Three degrees of freedom ( X , Y , Z ).
R 51: x – direction; R 52: x and y directions ; R 53 : all 3 directions.
Maximum Displacement : +/- 75 mm (150 mm p-p) dynamic
Maximum Velocity : > 1.2 m/sec
Maximum Acceleration : >1 g at the maximum load
≈ 1.6 g for specimen weight 500 kg
≈ 2.2 g for specimen weight 250 kg
Maximum Load : 2000 kg
Frequency range : 0.5 Hz to 50 Hz
Servo Valve : The Servo-valve has a capacity of ≈ 2 t combined with:

A hydraulic valve GPM two stage Moog servo valve,
Delta-P compensation,
Displacement scensor,
Local 10-gallon accumulators at manifold for line pulsation control and maximum high velocity performance.

Analog Control System :
Industrial GS 2000 PID controller
digital Control System :
Digital System with 3 channels (ANCO) together with a Dell Pentium IV PC
It also includes 8 channels ADC with AA filters and 3 channels with Piezoelectric feedback accelerometers.