Effect of flame heat flux on thermal response and fire properties of char‐forming composite materials

Abstract

SUMMARY This study evaluates the effect of flame heat flux on the prediction of thermal response and fire properties of a char‐forming composite material. A simplified two‐layer flame model was developed and incorporated into a heat transfer thermal model to predict the thermal response and fire reaction characteristics of a burning material. A typical char‐forming material, E‐glass reinforced polyester composite, was used in the study. A cone calorimeter was used to measure the fire reaction characteristics of the composite. The flame heat flux in a cone calorimeter test setup was estimated using the simplified flame model. Thermal response and fire property predictions with and without the effect of flame heat flux were compared with experimental data obtained from the cone calorimeter tests. Results showed that the average flame heat flux of the composite in a cone calorimeter was 19.1 ± 6 kW/m² from model predictions. The flame had a significant effect on the thermal response and fire properties of the composite around the first heat release peak but the effect decreased rapidly afterwards. Copyright © 2012 John Wiley & Sons, Ltd.

A simplified model for predicting the ignition of FRP composites with validation using intermediate‐scale fire experiment data

“…The average flame fluxes arriving at the composite were determined as 4.5 and 3.5 kW/m 2 at heat flux levels of 35 and 45 kW/m 2 , respectively . The effective flame heat flux was approximated by Equation .…”

“…In , the flame effect under different external heating flux for the same FRP composite material in this paper was studied. It was reported that the maximum flame effect was achieved at the very beginning of flaming ignition and then decreased almost linearly and became very small (approaching to zero) at the end (Figure ).…”

“…In , the flame effect under different external heating flux for the same FRP composite material in this paper was studied. It was reported that the maximum flame effect was achieved at the very beginning of flaming ignition and then decreased almost linearly and became very small (approaching to zero) at the end (Figure ). According to this observation, the effective flame heat flux arriving at the specimen is approximated as a linear function of the average flame flux as Equation : Where is the average of effective flame flux, is the effective flame flux function of time, and t burn is burning time starting from flaming ending with extinguishment.…”

“…The solution with combustion flame effect is given in Equation (12a), in which the effective flame heat flux q_ 00 F and the effective heat convection h eff are unknown. In [30], the flame effect under different external heating flux for the same FRP composite material in this paper was studied. It was reported that the maximum flame effect was achieved at the very beginning of flaming ignition and then decreased almost linearly and became very small (approaching to zero) at the end (Figure 2 [30]).…”

Study of thermomechanical coupling in carbon fibers woven‐ply reinforced thermoplastic laminates: Tensile behavior under radiant heat flux

“…[ 40 ] Recent studies specifically have addressed the questions related to the tensile behavior of carbon/polyphenylene sulfide (C/PPS) under very high‐temperature conditions, with an emphasis on the evolution of the mechanical properties along with temperature higher than the onset of thermal decomposition temperature. [ 19,20 ] To better understand the changes in the thermal and mechanical behaviors of TP‐based composites under fire exposure the first step usually is to investigate the influence of temperature resulting from homogeneous [ 30 ] or heterogeneous temperature conditions. [ 31,32 ]…”