10. A Support Platform for Distributed Hybrid Testing

Distributed hybrid testing offers a promising approach to use resources from geographically separate laboratories in a highly efficient way, to perform more complex, larger-scale tests than are possible in most individual laboratories. The method involves splitting a structure into a set of substructures (some tested physically, some modelled numerically) located in different laboratories. Simulation of the full structural response involves simultaneous testing of the substructures with feedback of data between them, requiring fast communication through computer networks. To handle systems involving rate dependence, there is a desire for test speed to approach real time. In addition to the increased difficulty of tracing errors caused by the distributed environment, organizing and planning distributed experiments creates much more complexity than in single-laboratory hybrid tests. This points to the importance of a platform to support the testing activities. This platform has been achieved by means of a specification called Celestina, created at the University of Oxford. Celestina provides a framework for conducting the experiment workflow. It provides a specification for the services to be implemented under three main headings of networking, test definition and experiment execution, and supports to data exchange during a test. It does not force any particular implementation, which can be independently developed and implemented under this framework, nor does it restrict the actual method of data exchange. In this article we discuss the design and conception of the specification as well as one implementation that has been validated through a series of substructured “numerical experiments” in partnership with the University of Kassel.