The George E. Brown, Jr. Network for Earthquake Engineering Simulation

Equipment

1. Facility
2. Centrifuge
3. In-Flight Robot
4. Laminar Boxes
   1. 1D Large Laminar Box
   2. 1D Small Laminar Box
   3. 2D Laminar Box
5. Shakers
   1. 1D Shaker
   2. 2D Shaker
6. Split Boxes
   1. Dynamic Split Box - 1H 1V
   2. Dynamic Split Box - 2H
7. Rigid Boxes
8. High-Speed Camera
9. Sensors
10. Data Acquisition

DAQ Hardware

The geotechnical centrifuge data acquisition hardware is comprised of National Instruments PXI and SCXI based architecture. M-series multi-function data acquisition cards perform high-speed A/D conversions to signals provided by SCXI conditioning units. Main features of the system include:

• Simultaneous acquisition of 128 channels of data at up to 30,000 samples per second
• Bridge completion for both quarter and half bridge strain gauges
• Multiple hardware filtering and amplification settings
• Rapid sensor to hardware configuration through standard RJ12 connections
• Triggering allows for inter-hardware data acquisition
• Analog outputs to control centrifuge based accessories

Additional hardware is used for advanced sensors and is described in the sections on tactile pressure sensors and bender elements.

DAQ Software

The data acquisition software in use at the geotechnical centrifuge facility is the second version of a highly customized LabVIEW based program. Initially designed for the Rensselaer centrifuge, it has been adopted by facilities around the world. The software is powerful, detailed, flexible and easy to use. Key features include:

• Software triggering of centrifuge accessories, e.g., the shaking platforms and high-speed camera
• Synchronization of data acquisition with additional sensor systems
• Software nulling of gauge sensors, e.g., strain gauges, pore-pressure transducers, and load cells
• Data may be monitored in engineering units or raw voltage

Our DAQ system is provided by Bloomy Controls, Inc. More information about our system is available here.