Fire Safety Science Digital Archive

A new computational procedure for analysis of the melting and spread of polymers under fire conditions is presented. The method, termed Particle Finite Element Method (PFEM), combines concepts from particlebased techniques with those of the standard finite element method (FEM). The key feature of the PFEM is the use of an updated Lagrangian description to model the motion of nodes (particles) in the thermoplastic material. Nodes are viewed as material points which can freely move and even separate from the main analysis domain representing, for instance, the effect of melting and dripping of polymer particles. A mesh connects the nodes defining the discretized domain where the governing equations are solved as in the standard FEM. An incremental iterative scheme for the solution of the non linear transient coupled thermal-flow problem is used. Examples of the possibilities of the PFEM for the modelling and simulation of the melting and spread of polymers under different fire conditions are described. Numerical results are compared with experimental data provided by NIST.