Numerical simulation of composite structure response from a fire plume

This study is on development of numerical algorithms and models for simulation of a composite structure response from a fire. A thermo-mechanical damage model for the composite material is developed based on homogenization techniques consisting of fiber, resin, char and gas. Transport equations are derived using phase-averaging principles that employ a Darcy law to account for gas flow in the structure. The mechanical response in the composite is determined through solution of modified linear elasticity equations that account for gas pressure and thermal expansion. The flow field from the fire plume is modeled using the 2D Navier-Stokes equations supplemented with a transport equation for thermal energy and solved using a vorticity-streamfunction approach. Coupling of the structure and fire models is based on the use of a level set method. Numerical simulations of a two-dimensional composite cantilever beam subject to convection heat loading from a hot plume are presented. Results show that during early stages of heating, the gasification of the resin creates local stress concentrations due to the increase in pressure and thermal expansion. The peak stress is shown to be sensitive to the rate of heating and transient flow effects in the beam.