Studies on Lightweight Glass Fibre-Resin Composites by Destructive and Nondestructive Methods

The relationship between the structure and properties of very lightweight glasswool-phenolformaldehyde resin composites was studied by measuring the composite strength and elasticity properties. The fibre structure of the examined composite (den-sity 10... 40 kg/m3 and resin concentration 1... 13 w-%) was found to be almost random in two directions, while in the third direction there were relatively few fibres. It was found that the elasticity properties of the composite after compression decrease as a function of time and the degree of compression. This phenomena can be explained by the static fatigue of the glass fibres, which means that their strength depends on the length of time that a load is applied or on the loading rate [1]. It was shown that the values of destructive tests (tensile strength), as well as such material parameters, like density and binder phase concentration are possible to be determined with nondestructive tests (the damping test)