Bearing capacity assessment for a timber girder when subject to a localised fire

Computational Civil Engineering Conference 2019

土木建筑工程

Kmiecik, K.^1

Institute of Building Materials and Structures, Faculty of Civil Engineering, Cracow University of Technology, Cracow

31-155, Poland^1

关键词: Accurate estimation;    Capacity assessment;    Combustible materials;    European Standards;    Fire safety requirements;    IS implementation;    Load-bearing capacity;    Timber structures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/586/1/012001/pdf
DOI  :  10.1088/1757-899X/586/1/012001

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

Timber girders are often used as roofs in large-area buildings. One of the most important issues concerning the design of timber structures are fire safety requirements. Safe design requires adequate knowledge and modelling of the physical and chemical reactions inside the timber members exposed to fire. Wood is a combustible material. At 300°C the pyrolysis takes place which cause loss in mass and decrease the strength and mechanical properties. European standards introduce simplified methods for assessing load-bearing capacity in fire conditions. The second approach is advanced numerical modelling. This paper presents results from numerical studies on fire resistance of timber girder when subject to a localised fire. The numerical simulations have been performed with application of the SAFIR computer program. The numerical model of a timber girder was made. European standards recommend estimating the fire resistance of a structure based on the ISO fire curve. The advantage of such an approach is simplicity. It can lead to overestimating load-bearing capacity. Therefore, the cost of construction and fire protection will be higher. Another approach is implementation of appropriate fire models. Then, determining the temperature-time relationship for the analysed structure members. In this paper localised and IS0 fire were assumed. The heat was applied for three sides of the beam. An uneven cross-section along the length was also assumed. The obtained results indicate that advanced numerical analysis allows for a more accurate estimation of the load-bearing capacity of timber elements exposed to fire.