Finite element analysis of heat transfer through timber elements exposed to fire

Abstract Since timber is a combustible material, its safe use in construction will depend on a proper knowledge and modelling of the physical and chemical reactions involved in the pyrolysis, that affect the temperature growth and thus the performance of timber in fire. Based on the comprehensive one-dimensional analytical models of the pyrolysis available in the literature, it is required to implement a predictive FE model via a user-defined subroutine in the dedicated commercial software in order to describe more closely the real physical phenomena that undergo timber exposed to fire. This paper presents the implementation of the UMATHT subroutine in the Abaqus software. The obtained results showed a fairly good agreement with experimental ones from the literature. However, at this stage of the study the pyrolysis is taken into account implicitly in the developed UMATHT through gradually modified thermo-physical properties of the timber, as commonly adopted in the published literature. Work is now in progress to implement explicitly the different reactions of the pyrolysis in the developed UMATHT.

[1]  Agnese Menis.  Fire resistance of Laminated Veneer Lumber (LVL) and Cross-Laminated Timber (XLAM) elements , 2012 .

[2]  R. Bilbao,et al.  Modelling of the pyrolysis of wet wood , 1996 .

[3]  K. Cen,et al.  Modeling pyrolysis of wet wood under external heat flux , 2007 .

[4]  Y. Mai,et al.  Thermal conductive and electrical properties of polyurethane/hyperbranched poly(urea-urethane)-grafted multi-walled carbon nanotube composites , 2011 .

[5]  Mahen Mahendran,et al.  Numerical studies of gypsum plasterboard panels under standard fire conditions , 2012 .

[6]  Marc L. Janssens,et al.  Modeling of the thermal degradation of structural wood members exposed to fire , 2004 .

[7]  A. P. Schniewind,et al.  Performance of structural wood members exposed to fire , 1975 .

[8]  Andrea Frangi,et al.  Charring rates and temperature profiles of wood sections , 2003 .

[9]  Geoff Thomas,et al.  Modelling thermal performance of gypsum plasterboard‐lined light timber frame walls using SAFIR and TASEF , 2010 .

[10]  Andrea Frangi,et al.  Fire design of steel-to-timber dowelled connections , 2010 .

[11]  Greg Turk,et al.  Buckling of timber columns exposed to fire , 2011 .

[12]  Bertil Fredlund,et al.  Modelling of heat and mass transfer in wood structures during fire , 1993 .

[13]  Colomba Di Blasi,et al.  Analysis of Convection and Secondary Reaction Effects Within Porous Solid Fuels Undergoing Pyrolysis , 1993 .

[14]  Frank E. Woeste,et al.  Replicate fire endurance tests of an unprotected wood joist floor assembly , 1984 .

[15]  H. Baum,et al.  Experimental and theoretical investigation of heat and mass transfer processes during wood pyrolysis , 2010 .

[16]  Goran Turk,et al.  Fire analysis of timber composite beams with interlayer slip , 2008 .