Fatigue Analysis of Composite core Sandwich Panels under Three-point Bending Loading

The use of sandwich panels has become very popular in recent engineering designs when the weight of the pieceor structure is important and we are looking to reduce weight while maintaining strength. The mechanicalproperties of these types of structures, including yield stress, fatigue behavior and life estimation, failure modes,natural frequencies and resonance phenomena, etc., are influenced by various factors, including geometric andenvironmental factors. In this study, influences of geometric factors, loading frequencies and initial crack positionon the fatigue life of composite sandwich panels and their failure modes are investigated using numerical andexperimental methods. The research consists of two parts including numerical analysis using finite elementsoftware and experimental tests in which the samples are under three-point bending loads. Experimentalspecimens are consisted of an XPS-foam core and Fiberglass face sheets. The results showed that by reducing thewidth of the beam, there was a significant effect on the final life of the samples and reduced the life of the sampleslinearly and the start of crack path and final failure mode of different samples were different with each other. Withenhancing distance of the initial crack from the center of the beam, the life of the samples increased apparentlywithin a different final fracture mode in specimens. Loading frequency didn’t have noticeable effect on sample’slife.