Charring of Timber with Fissures in Experimental and Numerical Simulations

Abstract

Drying fissures occur in some timber structures what can lead to an issue for a mechanical resistance of these structures. There is no proposal to quantify the effect of various fissures and gaps on the charring of timber structural members. Therefore, this contribution deals with the numerical and experimental analysis of selected dimensions and number of fissures. The numerical analysis was conducted in a software based on FEM. There were created models with local fissures and simplified “smeared” models. The samples were tested in a cone calorimeter. There were two types of samples. The charring depth was measured from a split cross-section for the first group of samples. Temperatures were measured by means of thermocouples for the second group of samples and the charring depth was calculated based on these temperatures. The aim of this paper is to compare values of the charring rate and depth for the samples with different fissures. In terms of results, the bigger fissures or larger quantity of fissures should be considered by means of advanced design methods, or by increased value of the charring rate. However, the smaller fissures can be neglected.