Damage Mechanism of a Sandwich Material Tested Under Static and Cyclic Loadings in a Three Points Bending Experiment

This paper presents the results of an experimental investigation on the damage mechanism of a sandwich material, tested under static and cyclic loading conditions in a three points bending test. Four loading levels were considered for different number of loading cycles and rates of loading. The samples were tested using a Universal machine (Zwick Roelle) allowing a loading capacity of 5 kN, monitored by a computer. The main results obtained show that for the three loading rates investigated, increasing the cyclic loading level causes a decrease in the deformation energy of the sandwich material. This observation was confirmed by the evolution of the damage mechanism related to the number of cycles applied to the sample. When analyzed by means of the optical microscope, the damage and failure mechanisms were found to be linked to the delaminating of the Core-thickness and failure of the fibers