An Adaptive Controller for Hybrid Fire Testing

To experimentally assess the fire resistance of civil structures, testing whole structures is very costly but the standard tests on individual structural elements can sometimes be too simplistic, regarding their boundary conditions. Hybrid fire testing is then a promising approach to overcome some of these limitations. In order to perform such tests, the existing procedures make use of estimated parameters from the tested structural element. Furthermore, the actuators system of the experimental set-up must include a direct displacement feedback control, leading to difficulties in the case of stiff elements. This paper will present a method to avoid these two constrains of the previous approaches. A new hybrid fire testing procedure is designed, permitting the control of the actuator system without explicit knowledge of the structural element position. Then an adaptive controller dedicated to this procedure will be described. A virtual environment has been developed in order to assess the behavior of the presented testing procedure and controller, through a virtual hybrid fire test. It is subject to assumed experimental imperfections such as noise, quantization and actuator non-linearities. A test case is performed within this framework, showing good agreement with the expected results. Finally, preliminary experimental hybrid test case performed at ambient temperature is presented.