The influence of elevated temperatures on stiffness and strength of composite face sheet and polyethylene terephthalate foam cored sandwich beam has been experimentally investigated. Standard test methods and analytical failure models were used to determine the effect of elevated temperatures. The authors examined E-glass/epoxy cross-ply face laminates, polyethylene terephthalate foam, and sandwich beams consisting of glass/epoxy face laminates and polyethylene terephthalate foam core loaded in four-point flexure. The tensile properties of the face laminate were examined over a temperature range from 25 to 175°C. Compression and shear tests on the face laminate, polyethylene terephthalate foam, and sandwich beams were performed at temperatures up to 100°C. The face laminates exhibited moderate reductions of Young’s modulus and tensile strength, while the compressive strength, shear modulus, and shear strength substantially decreased at elevated temperatures. Similarly, the compressive and shear moduli as well as the compressive strength of the polyethylene terephthalate foam decreased substantially by exposure to a temperature of 100°C. The failure mode of the sandwich panels was observed to be highly dependent on temperature, distinguishing three basic failure modes, viz. core shear failure, indentation failure, and face wrinkling. The failure loads associated to these failure modes were calculated using models available in the literature. The failure loads were found to be consistent with the failure predictions and failure modes.
Full-scale tests of A-60 steel and FRD-60 aluminium and FRP bulkheads exposed to fire were carried out in order to compare their respective behaviours in terms of their ultimate load-carrying capacity beyond the prescribed 60 min threshold under thermomechanical loadings. These three materials were chosen as implementation within the SOLAS framework requires documenting a level of robustness equivalent to that of steel. This is a complex process since robustness is not clearly defined and no procedure exists to quantify it. It was found that robustness can be quantified as a time-to-mechanicalfailure and is highly dependent on the fire scenario (load, fire exposure, and boundary conditions).Regulatory codes and design practices were found to disregard specific properties of alternative materials, and only consider one default scenario, which is not representative of a real-life situation. It was concluded that specific properties of alternative materials should be used and equivalence in terms of safety should be documented through performance-based design, for instance risk analyses, instead of forcing requirements originally developed for steel structures on their lightweight counterparts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.