Anisotropic composite structure, liner and helmet comprising such a structure and use of and method of producing such a structure

The present invention relates to composite structures, preferably composite cellular or foam structures and more specifically composite cellular or foam structures used for protective head liner structures (e.g. in helmet liners), said composite structure comprising a plurality of core structures, made of a first cellular material, and a support material surrounding each core structure, the support material comprising a unitary body of a second cellular material having a plurality of recesses therein, each core structure being disposed within one of the a recesses in the unitary body of the support material. The cellular materials have when loaded in compression an elasto-plastic behavior with a plateau stress, followed by densification and when loaded in shear show plastic behavior with a strain at maximum load or failure strain larger than 8%, and the first cellular material has a higher compressive yield and plateau stress as compared to the second cellular material.