No abstract

DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Summary Nowadays, buildings contain more and more synthetic insulation materials in order to meet the increasing energy‐performance demands. These synthetic insulation materials have a different response to fire. In this study, the mass loss and flammability limits of different sandwich panels and their cores (polyurethane (PUR), polyisocyanurate (PIR) and stone wool) are studied separately by using a specially designed furnace. Expanded polystyrene and extruded polystyrene are tested on their cores only. The research has shown that the actual mass loss of synthetic and stone wool‐based cores is comparable up to 300 °C. From 300 °C onwards, the mass loss of PUR panels is significant higher. The mass losses up to 350 °C are 7%, 29% and 83% for stone wool, PIR and PUR respectively, for the influenced area. Furthermore, delamination can be observed at exposure to temperatures above 250 °C for the synthetic and 350 °C for the mineral wool panels. Delamination occurs due to the degradation of the resin between core and metal panels and the gasification of the (PUR) core. The lower flammability limits have been established experimentally at 9.2% m/m (PUR) and 3.1% m/m (PS). For PUR, an upper limit of 74% was found. For PIR and mineral wool, no flammability limits could be established. Copyright © 2017 John Wiley & Sons, Ltd.

To understand sandwich panel behaviour under fire, expensive full-scale tests, or potentially more efficient fire-structure simulations can be carried out. However, these simulations have only been demonstrated to work for specific applications, either on the global scale (a fire on a simple panel) or on the small scale (a temperature load on a single screw connection), often loaded by a standard fire curve. In this paper, the quality of simulations for combined situations is investigated, i.e. a furnace fire on a set of panels including details and connections. First two existing tests are introduced, a sandwich panel façade test and a studs bolt test, followed by the presentation of their basic fire-structure simulations. In general, the heat transfer analyses agree well with the tests, whereas the structural response analyses need investigation: For the first test, out-of-plane deflections are overestimated at the beginning of the test. A parameter study indicates that this is most likely due to adhesive decomposition, resulting in face delamination and related instabilities. For the second test, the basic simulation does not show any failure, whereas the test failed by vertical bearing. However, with a two-scale model the ultimate load is estimated, and increasing vertical displacements and the onset of vertical bearing are predicted. It is concluded that future tests should include more simulation-relevant measurements. Also, global-scale models need to include features specific to the structure to be simulated, only known after tests and basic simulations, and connections may be decisive for global-scale behaviour, which can be incorporated by a two-scale model. Finally, the tests exhibited complex behaviour across different scales, and modifications and improvements of the simulations increased their fidelity. Therefore fire-structure simulations should always be verified with tests and compared with basic simulations, and modifications in the simulation models should be anticipated.