Experimental Investigation of Mechanical Behaviour and Damage of Bio-Sourced Sandwich Structures Based on Date Palm Tree Waste and Cork Materials

The date palm is a giant plant that must be cleaned annually, which can be the first source various raw materials compared to other woods that are cleaned once every four years, such as cork. In Algeria, there are millions of palm trees that produce a significant amount of raw materials annually, but unfortunately they are not exploited in industry. This paper presents an experimental study on mechanical behaviour of four bio-sourced sandwich materials differentiated by their core types. The skins of these sandwiches are made composite material composed of rachis fibers and epoxy resin; however the cores are made of: 1) raw petiole and petiole agglomerate with two sizes (0-1 mm and 1-3 mm) and 2) cork agglomerate for comparison. The comparison between these sandwiches is based on the overall stiffness which is determined by three point bending tests. The results obtained for all sandwich materials show that the overall stiffness of the Petiole agglomerate with the size (0mm-1mm)/rachis fibers-epoxy resin is higher than the other sandwiches. Thus, we have carried out a complementary damage study to this last sandwich material based on delamination tests. It turns out through this study the good resistance of this new sandwich to delamination compared to other previously studied materials.