Innovative sandwich structures based on woven and knitted distance fabrics: A review

Some ten years ago, we have introduced the concept of sandwich structures, based on three-dimensional or distance woven fabrics. Five years later, we have shown that distance knitted fabrics show some additional advantages for application in composite sandwich structures. Woven sandwich structures offer important advantages which are related to the integral core-skin structures. Knitted sandwich structures offer additional advantages : excellent drapability and possibility to have a wide variety of skin structures. In this paper, we will present a review of the most recent development in the processing, properties and applications of this new class of sandwich structures.