Time-to-failure of Compressively Loaded Composite Structures Exposed to Fire

Abstract

A combined thermal-structural analysis methodology based on finite element modeling is developed for the analysis of composite structures exposed to high temperatures due to fire. A simplified heat transfer model proposed by Lattimer is adopted for the thermal response model to determine temperature distributions in composite structures with and without insulation while an assumed strain solid shell finite element formulation is adopted for the structural response model with a material model that takes into account the effects of temperature on modulus and charring. Numerical analyses are carried out to determine the time-to-failure via the global buckling of simply supported and clamped wide columns of an E-glass/ vinylester woven composite material with and without insulation subjected to heat flux and compression. Large deflection non-linear analyses are also conducted to determine the displacement of the columns as the temperature changes. The beneficial effect of insulation on time-to-failure is demonstrated via numerical calculations. Sensitivity analyses are carried out to examine the effect of variation in the glass transition temperature on the time-to-failure of the composite columns.

Keywords

fire safety time-to-failure composite structures in fire.

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