Validating hybrid fire testing with full-physical twin experiments

Abstract

Real fire incidents show that structural systems have specific fire-induced redundancies that make them perform better than classical structural fire analysis predicts. Properly validated hybrid fire testing has the potential to tap into such redundancies for designs. In this study, we conceived and implemented a comprehensive and novel physics-based validation strategy for hybrid fire testing. We developed a laboratory-scale thermo-mechanical proof-of-concept problem that is representative for structural systems exposed to compartment fires. We solved the proof-of-concept problem using our novel thermo-mechanical hybrid solution procedure (Schulthesset al.2020Comput. Struct.238, 106301 (doi:10.1016/j.compstruc.2020.106301)) and compared the resulting hybrid model response against the results from a full-physical laboratory set-up of the same proof-of-concept problem, which we call a full-physical twin experiment. Full-physical twin experiments constitute the top layer of a suite of benchmark tests any specific hybrid fire testing procedure must pass to qualify not only as theoretically accurate and correctly functioning but also (and more importantly) as physically sound and able to yield realistic simulation results. This paper delivers such a first-of-its-kind physics-based validation, and in doing so, the first comprehensively validated method for hybrid fire testing—a method that now allows fire test facilities to conduct meaningful full-scale hybrid fire tests of entire structural systems.