Determining mechanical and acoustical behaviors of all-recycled PP sandwich structures with bi-directional sinusoidal corrugated core

By recycling the waste polymer material and using it in weight reduction studies of electric vehicles, a double-sided gain is achieved against environmental pollution. Sandwich structures with prismatic cores obtained by recycling waste polymers can be used in structural applications of light and heavy commercial vehicles and public transportation vehicles that carry cargo and passengers. These sandwich vehicle parts could help to increase the max. range and load-carrying capacity of electric vehicles. In this study, sandwich plates with prismatic egg-box cores were produced with waste Polypropylene. Since the materials are collected from different waste sources, the physical properties (additive ratio, secondary substance determination, density) of the recycled material were measured. Thereafter, hardness, quasi-static flatwise and edgewise compression, and 3-point bending tests were done to determine the mechanical properties of the structure. After that, dynamic compression and 3-point bending tests were performed to determine the strength and impact energy absorption capacity of the structure in collision situations. Finally, impedance tube tests were carried out for the acoustic characterization, which is one of the important parameters affecting interior cabin comfort, and Sound Transmission Loss (STL) and Sound Absorption Coefficient (SAC) values of the structure were determined.