A simple hybrid testing approach for dynamic analysis of civil structural control devices

摘要

Effective real-time testing of structural control devices relies on a hybrid test systemthat couples virtual structures under dynamic loading with physical sub-structures ordevices in a dynamic test rig. The use of sensors and actuators in a closed-loop feedbacksystem maintains the dynamic equilibrium of the overall system comprising the physicaltest article and virtual modelled structure. The virtual-real hybrid testing method thusalleviates much of the time and cost associated with full-scale testing and enables teststhat would be infeasible without full-scale complete structural tests. Thus, it can reducethe uncertainty in designing such a full scale test by testing, in hybrid hardware in theloop fashion, the devices and sub-systems required to ensure the best overall full-scaleexperimental design. Hence, a major outcome is the savings in the cost, time andcomplexity of the resulting full scale experiment. To accomplish this goal, this researchpresents simple, cost-effective and robust hybrid test system, and outlines solutions tothe major issues faced in developing any hybrid system. The overall approach is centredon the dSpaceTM real-time control system development tool. The major issues indeveloping a hybrid system are: minimal signal processing lag, optimised sensingresolution and bandwidth, and efficient model computation. All three affect the abilityof the system to maintain dynamic equilibrium of the overall virtual-physical system,and thus provide an accurate test. The final system readily accommodates non-linearsingleand multi-degree-of-freedom models and an operating bandwidth of 1 kHz. Testresults and experimental outcomes are based on studies of a linear single degree offreedom structure and a non-linear rocking wall system that includes impact loads andtiming subject to random ground motions. The results clearly illustrate systemsimplicity, efficacy and how they can be used to illustrate the potential outcomes of fullscale experiments but at simple, fast low cost level.Keywords: