Mechanical properties of composite panels based on woven sandwich-fabric preforms

An overview of the mechanical properties of the core of woven sandwich-fabric panels is given. These materials provide a new type of sandwich structure with a high skin-core debonding resistance and the potential for cost-effective sandwich construction. The sandwich-fabric prc forms are produced by a large-scale textile weaving process (velvet weaving). The basic mechanical properties of the sandwich core (compression and shear) were evaluated and compared with those of other core materials. There is a large variety in possible core layouts and thus mechanical performance for sandwich-fabric panels. Acceptable mechanical properties for cores of higher thickness (higher than 10 mm) can be obtained by weaving part of the pile fibres in the core under angles of +/-45 degrees, by creating networks of piles at lower degrees of stretching and sufficient pile density, or by filling the core with foam. There appears to be a strong synergistic effect between pile and foam properties in the sandwich core. (C) 2000 Elsevier Science Ltd. All rights reserved.