This paper reports on changes to the mechanical properties of woven glass laminates with polyester, vinyl ester and phenolic resins during fire exposure. Two sets of experiments were carried out. First, unstressed laminates were exposed to a constant one-sided heat flux (50 kW m 2) for various times, and the residual post-fire strength at room temperature was reported. In a second series of experiments, laminates were tested under load. The times corresponding to a given loss of properties were 2-3 times shorter than in the previous case. It was found in both cases that modes of loading involving compressive stress were more adversely affected by fire exposure than those involving tension. A simple ‘two-layer’ model is proposed, in which the laminate is assumed to comprise (i) an unaffected layer with virgin properties and (ii) a heat-affected layer with zero properties. For residual properties after fire, the ‘effective’ thickness of undamaged laminate was calculated using this model and compared with measured values. A thermal model was employed to predict the temperature and the residual resin profile through the laminate versus time. Comparing the model predictions with the measured values of effective laminate thickness enabled simple criteria to be developed for determining the position of the ‘boundary’ between heat-affected and undamaged material. For post-fire integrity of unloaded laminates, this boundary corresponds to a Residual Resin Content (RRC) of 80%, a criterion that applies to all the resin types tested. For polyester laminate under load in fire, the boundary in compressive loading (buckling failure) appears to correspond to the point where the resin reaches 170 C. In tensile loading, significant strength is retained, because of the residual strength of the glass reinforcement. The model was used to produce predictions for ‘generic’ composite laminates in fire.

A thermomechanical modelling approach is proposed for estimating the residual properties of bre reinforced polymer composites damaged by re. The modelling was carried out in two parts: (i) prediction of the extent of thermal decomposition (or charring) using a thermal model; and (ii) prediction of the post-re behaviour using a two layer model that combines the properties of the undamaged laminate and the residual char. Fire experiments were performed on glass-polyester, vinyl ester, and phenolic laminates using a cone calorimeter operated at heat uxes in the range 25-100 kW m -2, for times up to 30 min. After cooling to room temperature the thickness of the thermal damage layer was determined, along with values of the residual tensile, compressive and exural properties. For the 'two layer' model it was found that the eVective boundary between char material and undamaged laminate corresponded to the point where the residual resin content (RRC) of the laminate was 80%. Surprisingly, this value was found to hold for all three resin types tested. Using this RRC value, excellent agreement was found between the measured and predicted post-re char thickness and the residual mechanical properties. The approach presented is the rst reliable method for accurately predicting the residual properties of composites after re.

An experimental and modeling study is conducted on the vacuum consolidation of commingled glass/thermoplastic composites as part of a larger project on manufacturing large monolithic structures from these precursors. Two polyethylene terephthalate (PET) matrices are employed: semicrystalline PET and an amorphous PET copolymer. Samples of commingled fabric are processed into consolidated composites by means of both a convective oven, as will be used in practice, and a small-scale experimental characterization rig, designed to measure consolidation accurately. The samples are then cooled to room temperature. In this article, the thermal and consolidation characterization of these fabrics is reported. Thermally induced consolidation is observed to occur in two stages: a low temperature solid state de-bulking near to Tg, followed by full melt impregnation at a higher temperature. Both stages are modeled separately using an empirical model based on the Kamal equation. The measured consolidation versus time profiles suggest a rapid impregnation and wetting of the fibers, occurring near to the melting point of the semicrystalline polymer. The PET melting endotherm and crystallization exotherm have little effect on the observed thermal profiles, suggesting that these effects can possibly be neglected when modeling the process.

Thermoplastic filament winding with in line melt impregnation has been investigated for the manufacture of continuous glass fibre reinforced thermoplastic pipes. With polyethylene matrixes it was found that the high melt viscosity hindered full melt impregnation and resulted in high pull forces in the case of pipe grade polyethylene. Using a lower viscosity polyethylene it was possible to operate the melt impregnation process, but the product obtained exhibited a high void content. Surprisingly, it was found that filament winding resulted in a considerable decrease in void content, to an acceptable level. It was found possible to wind good quality pipes and achieve high failure pressures that fully reflected the strength of the reinforcement.The non-linear strain response of glass-polyethylene pipes can be modelled using laminate theory modified to take account of the non-linearity of the matrix and the change in fibre angle that occurs as the pipe deforms.

The structural performance of a symmetric steel to composite bonded joint has been examined. Numerical predictions and experimental results on the mechanical strength of the joint are presented. The experimental data and the findings from this study provide useful guidelines to ship designers for using large composite structural components in steel ships.