X-joints in composite sandwich panels

The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for applying such panels is the design and manufacturing of adequate joints between panels. This is especially true for X-type of joints. This article shows how this type of joint can be analysed in a manner which can be suitable for design purposes. It is shown how delamination can be treated by applying a well established fracture mechanics technique. Some comparison is made with a structural test on a full scale X-joint specimen. Fatigue analysis is not referred to.