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Lookup NU author(s): Professor Geoff Gibson,
Dr George Kotsikos,
Pietro Di Modica
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
This paper discusses the modelling of failure times of aerospace carbon-epoxy laminates under constant in-plane compressive stress and one-sided heat flux. These are conditions relevant to post-crash fires and similar occurrences. The thermal field within laminates exposed to fire can be modelled using the Henderson Equation, as, for instance, with the COM-FIRE model. The main difficulty lies in acquiring the necessary mechanical data to model the failure event under these conditions. Large numbers of mechanical measurements over a temperature range well beyond Tg, are not a practical option. Instead, the measurement of simple matrix-influenced properties, was investigated: compressive strength (CS), interlaminar shear strength (ILSS) and Young's modulus from dynamic mechanical analysis (DMA). It was found that these properties do not all follow the same property vs. temperature law. The strength-influenced properties (CS and ILSS) behave similarly and drop off more rapidly as a function of temperature than the Young's modulus. For the mechanical modelling an average strength approach was used, which, combined with the thermal modelling, gave reasonable predictions of the time-to-failure for laminates 5-15mm thick and heat fluxes of 75-185 kW/sq.m. It is proposed that, by expressing stress as the ratio of applied stress/failure stress, it should be possible to use the same model for laminates with different ply sequences.
Author(s): Gibson G, Kotsikos G, DiModica P
Publication type: Conference Proceedings (inc. Abstract)
Publication status: Published
Conference Name: FRPM 2015, 15th European Meeting on Fire Retardancy and Protection of Materials
Year of Conference: 2015
Acceptance date: 24/04/2015
Date deposited: 28/01/2016