A software independent tool for mapping thermal results to structural model

• Present a stand-alone tool for mapping results from thermal to structural models.
• The tool is based on fundamental concepts of finite elements and shape functions.
• The approach is useful for conducting sequential thermal–structural analysis.
• The tool is written in MATLAB and can interface with any commercial software.
• Several verification cases on accuracy of structural temperatures are described.

In order to model the structural behavior under fire, three separate analyses need to be conducted: (a) fire propagation and growth (fire modeling), (b) heat transfer in structural members due to fire, and (c) structural analysis to account for both thermal and mechanical load. Fire modeling is conducted with computational fluid dynamics (CFD) approach. Typical heat transfer analysis is conducted using finite element analysis (FEA) approach employing solid 3D or 2D shell elements. Structural analysis is often conducted using FEA approach but employing beam and shell elements, especially for large structures.Common outputs of a CFD fire model relevant for a structural fire analysis are heat flux and temperature field, which are input to the heat transfer model as thermal boundary conditions. Subsequently, the transient temperatures computed by the heat transfer analysis in the structural members are inputs to the structural analysis model. However, this transfer of data is complicated because of the difference in the type of finite elements and level of discretization used in each of these two analyses. A software independent mapping tool is therefore required to transfer the thermal data from heat transfer model to structural analysis model.This paper discusses a novel methodology that was developed to map thermal data from a heat transfer model comprising solid finite elements to a structural analysis model comprising beam and shell elements. The methodology relies on the fundamentals of finite elements pertaining to the use of element shape functions and local or natural coordinates.