Software

To compensate for its relatively limited physical capability CU NEES site has placed much emphasis on software capability. Currently, numerical simulation is performed by OpenSEES which was modified to run completely on a realtime operating system, with direct access to the actuator controller. More recently, we “dissected” the code, and wrote a separate software-independent, library to connect a finite element code with the hardware.

As the software simulation runs, computation results from the computations are written to the SCRAMNet network, which are then used by the MTS controller as a new position command for the actuators. Then, in turn, measurements are collected by the MTS controller and written back to the SCRAMNet, which are then picked up by the software simulation as a restoring force to be used in subsequent computations. This entire sequence occurs every 0.97 milliseconds, or 1,024 times per second. Recent benchmarking indicated that we can support approximately 135 degrees of freedom in hard real time simulation of a nonlinear frame.

Partial list of CU-NEES software

OpenSees
OpenFresco
SIMCOR
Matlab/Simulink
Labview
SolidWorks
In-House FE Codes streamlined for FHT (work in progress)