Development of an Interface Between CFD and Fe Software

2013

The paper presents the assumptions and the issues that arise when developing an integrated modelling methodology between a Computational Fluid Dynamics (CFD) software applied to compartment fires and a Finite Element (FE) software applied to structural systems subjected to fire. In particular, a weak coupling approach used to simulate a fire exposed structure by modelling the fire development in the compartment, the heat penetration in the structure and the mechanical response is described. The advantages and the disadvantages of such a technique are highlighted compared to a full coupling that conversely takes into account all mutual interactions. The favourable aspect of computing the thermal response of the structure in the FE model in order to avoid modelling the structure in the CFD model is underlined, namely a sensitive reduction of computational demand. Finally, the study is enriched by an application of this methodology that concerns the simulation of a pool fire in an open...

Fire Safety Journal, 2018

2017

For the global modelling of building structures, that is, the modelling of the overall topology of the structure, not limited to certain connections or components, the coupling of CFD fire simulations and FE thermo-mechanical models can be carried out by either one-way coupling or two-way coupling. Unlike one-way coupling, two-way coupling considers the effect of the structural response on the fire propagation, an effect that so far has only been studied for a very limited number of cases. The first part of this paper investigates the feasibility of two-way coupling. Its components, fire simulation, heat transfer analysis, and structural response analysis are introduced first. These components are coupled by three steps: (i) coupling of fire simulations to heat transfer analysis; (ii) coupling of heat transfer analysis to structural analysis; and (iii) coupling of structural response to fire simulation, in which the latter is unique for two-way coupling. Then the implementations of ...

In Eurocode 1 part 2[1]nominal temperature fire curves and simplified models are given for the calculation of the fire loads and actions, but either they do not represent the real fire conditions arising in a fire event, leading to unnecessary over-designing, or have a limited field of application and cannot be used for new contemporary architectural designs or large industrial facilities.An alternative approach is the use of Computational Fluid Dynamics (CFD) with special codes specifically developed for the study of heat transport from fires, such as the Fire Dynamics Simulator of NIST. The models can be used as the base for developing performance based design in addition to the structural models used subsequently. This method, when used properlywithin its field of application,can help the engineer, through the simulation of fire scenarios, to study fire spread, smoke and toxic gas production and distribution, spatial and temporal temperature development in the compartment and in ...

2020

2014

Virtual fire testing could serve to improve the cost-efficiency of developing new composite materials for transport sector applications. Here, we present a simulation framework for the fire-respons ...

2014

No standardized material model is available for the calculation of steel components using the finite element method. With the objective to develop a three-dimensional constitutive model, first of all an investigation is carried out in as far as the one-dimensional stress-strain description of Eurocode 3-1-2 can be used as the basis for a programmed three-dimensional material model. It is found out that the constitutive relationship can be applied numerically in order to realize a program implementation of the constitutive model. The weak points of the formulation in terms of the mathematical description are indicated. As it is a rate independent constitutive equation, the question is raised whether the model is generally capable of representing creep. It is shown that the characteristics of creep are included in the constitutive model of Eurocode 3-1-2 and how creep is represented by that model. However, creep at constant temperature cannot be described because the strain depends only on stress and temperature. For the finite element program ABAQUS it is explained how the program implementation of a material model shall be carried out so that the model can be used for numerical simulation. A three-dimensional material model is developed based on the constitutive model of Eurocode 3-1-2 and the assumptions to be made here are shown.

Fire Technology, 2018