Articles_FireDynamics


Bayesian calibration and sensitivity analysis of heat transfer models for fire insulation panels

Chief author:

P.-R. Wagner

Governing institution:

ETH Z├╝rich, Switzerland

Publication date:

15.02.2020

Published in:

Engineering Structures (Vol. 205)

Link to Article:

Link to ScienceDirect

A common approach to assess the performance of fire insulation panels is the component additive method (CAM). The parameters of the CAM are based on the temperature-dependent thermal material properties of the panels. These material properties can be derived by calibrating finite element heat transfer models using experimentally measured temperature records. In the past, the calibration of the material properties was done manually by trial and error approaches, which was inefficient and prone to error.

In this contribution, the calibration problem is reformulated in a probabilistic setting and solved using the Bayesian model calibration framework. This not only gives a set of best-fit parameters but also confidence bounds on the latter. To make this framework feasible, the procedure is accelerated through the use of advanced surrogate modeling techniques: polynomial chaos expansions combined with principal component analysis. This surrogate modeling technique additionally allows one to conduct a variance-based sensitivity analysis at no additional cost by giving access to the Sobol’ indices. The calibration is finally validated by using the calibrated material properties to predict the temperature development in different experimental setups.


Fire protection provided by clay and lime plasters

Chief author:

J. Liblik

Governing institution:

Tallinn University of Technology, Estonia

Publication date:

2020

Published in:

Wood Material Science & Engineering

Link to Article:

Link to Taylor & Francis

Plasters are traditional surface finish materials in timber buildings. Today, the lack of fire performance data and design guidelines place such ecological materials at a disadvantage since plaster is not considered as a fire protection material for timber. This study aims to provide an up-to-date overview of performed fire tests accompanied by investigations on thermal properties of selected ready-mix clay and lime plasters. Design parameters of plasters for the fire design of timber structures are proposed following the safety philosophy of EN 1995-1-2. Numerical heat transfer simulations provide sufficient agreement with furnace test results for undercoat clay plaster. The mechanical fastening system of a plaster (e.g. reed mat) on timber demonstrates paramount importance when determining the charring rate of timber and the fall-off time of plaster. The structural integrity and fire performance of plasters should be further investigated due to their various recipes and numerous fastening systems on timber. Further research in full-scale is needed to confirm the recommended design parameters.