Facilities

Our facility will allow you to perform hard (i.e. deterministic) real time hybrid simulation (Delta t=1/1,024th of a second) using up to seven fast MTS actuators on a strong floor equipped with modular reaction walls using OpenSees, OpenFresco or SIMCOR. Existing capabilities allow us to analyze in real time up to ~140 degrees of freedom.

Hybrid simulation has benefited from increasing attention as a viable and economical means for conducting earthquake engineering research. This is likely in part due to the practical and intellectual appeal of taking a complex and/or large problem and reducing to more manageable components one or more of which are sufficiently will understood to be represented with existing computer modeling techniques. And the remainder, owing to uncertainties or other considerations, is represented physically in the laboratory and tested. These distinct components remain an integrated whole or a so called hybrid model that is the subject of either realtime or distorted time simulations. The distortion of time during a hybrid earthquake simulation has significant implications that limit the scope of work that can be carried out under such conditions. Most fundamentally is the limitation that the component(s) subject to physical testing behave in a rate or velocity independent manner.

Realtime hybrid simulation directly addresses this limitation very simply by accurately representing time in the simulated event. In doing so many of the assumptions that are the basis for time distorted hybrid simulations are no longer valid and additionally new technical challenges arise. The Fast Hybrid Testing facility at the University of Colorado has developed and continues to enhance and innovate a realtime hybrid simulation methodology that broadens the scope of possible work to include devices and materials that are rate sensitive.

The CU hybrid testing laboratory currently has a 3 degree of freedom limitation for the experimental test component.
The computational limitation of realtime hybrid testing is model dependant with the current demonstrated limit in the range of 130 degrees of freedom.
The platform developed for realtime hybrid simulation is flexible and expandable both in terms of what can be tested in the lab as well as what can be simulated within the computer.
The system level challenges of implementing and applying this technique have to a very large degree been successfully completed.
A variety of benchmark results have been established demonstrating a high level accuracy and versatility.

pdf The following report will provide you with an extensive assessment of our capabilities.

We are currently developing a new in-house streamlined finite element code for hybrid simulation (special attention being given to reinforced concrete frames) which would eventually allow us to substantially increase this size.