Opposed-flow flame spread over carbon fiber reinforced plastic under variable flow velocity and oxygen concentration: The effect of in-plane thermal isotropy and anisotropy

Abstract This work explores opposed-flow flame spread over carbon fiber reinforced plastics (CFRPs) with an emphasis on the in-plane thermal isotropy and anisotropy depending (CF) orientation. CFRP sheets different CF orientations were fabricated by laminating unidirectional prepregs in directions combusted via a chimney where flow velocity oxygen concentration variable. The limiting (LOC) under buoyant significantly increased orientation angle. At more than 45°, did not at all but was extinguished immediately after ignition even 60% O2. flammability of CFRPs angles 0°, 15°, 30° further investigated varying velocities concentrations. LOC higher that polymethyl methacrylate (PMMA) tested regardless response to varied overly sensitive almost constant 31% Meanwhile, LOCs 15° linearly decreased velocity. Flame for much faster PMMA because high conductivity fibers. rate affected 0° highest among three sheets. IR images used visualize temperature distribution during showed preheat region according Varying orientation, therefore, causes anisotropy, resulting differences rate. findings from this help us evaluate fire risk hazard serve discuss behaviors other anisotropic materials.