The 15 g-ton centrifuge, operational since 1981, is a Genisco 1230-5 accelerator modified for geotechnical applications. The symetrical dual-swing basket design will accelerate a 300 lb. 18x17.5x23 inch payload to 100g. A hydraulic drive system is employed to power the centrifuge. The hydraulic drive utilizes a 25 horse-power AC induction motor coupled to a variable displacement rotary piston pump. Hydraulic lines connect the variable displacement pump to a hydraulic motor which drives the main centrifuge shaft through a toothed belt. Currently the centrifuge speed is controlled manually by adjusting the pump displacement (hydraulic flow) while monitoring an rpm indicator. Future enhancements will utilize a computer controlled servo valve to vary the pump displacement under closed-loop speed control. This system will provide programable g vs. time profiles like 400g-ton and instructional centrifuges. Closed loop control will also provide accurate speed regulation immume to line voltage variations that cause speed instabilities in the current system.

Similar to the 400 g-ton centrifuge, the 15 g-ton centrifuge is equipped with a high-performance modular data acquisition system mounted at the center of the centrifuge arm. This system is capable of interfacing with all types of analog transducers used in geotechnical research. Acquired data is typically stored locally by the systems on-board hard disk and/or relayed via a high-speed wireless network to display terminals in the control room or elsewhere.

The 15 g-ton centrifuge is equipped with electrical and hydraulic/pneumatic sliprings. Electrical power for on-board equipment is supplied to the rotating centrifuge arm via a 56-channel electrical slipring stack. In addition to electrical power, video feeds from on-board cameras are routed through the sliprings to video monitors and video acquisition/machine vision systems. A three-channel hydraulic/pneumatic slipring is used to operate various types of actuators remotely from the control room, or deliver fluid to a test specimen in-flight.

The geotechnical centrifuge facilities at the University of Colorado, Boulder are available for use by research institutions and by private industry. Please contact Prof. Hon-Yim Ko (ko@colorado.edu) for information regarding the use of these facilities by outside parties and Robb Wallen (wallenr@colorado.edu) for specific questions regarding data acquisition and experiment control systems.