Co-authors​ :

 Telmo FERNANDES (PORTUGAL), Ricardo SOUSA (PORTUGAL), Fábio FERNANDES (PORTUGAL) 

For years, materials made from petroleum have been the go-to choice for protective equipment, with expanded polystyrene being the most prevalent option for the padding element. Nevertheless, lately, the need for sustainable solutions has led to the research of alternatives. Cork and its composites have caught the attention of several researchers and industries due to its properties, including high-performance ones such as protective gear, shock absorption, and crash-resistant systems. Their impressive sustainability profile sets these alternatives apart, with significantly lower greenhouse gas emissions than their petroleum-based counterparts. Recently, shear thickening fluids have been employed in many materials and structures, creating composite solutions with enhanced impact resistance. This hybrid solution has been previously tested in the form of sandwich structures where a thin shear thickening fluid layer is deposited between the outer cork layers. This study explores the non-Newtonian behaviour of shear thickening fluids, meaning their intrinsic ability to bolster viscosity and resistance in response to impact. In other words, this research explores the potential synergy of combining cork-based multilayers with shear thickening fluids in the form of sandwich structures. Several configurations are explored, varying the number and thicknesses of the cork layers. Additionally, strategies to investigate the effect of shear thickening fluid content on the composite structure impact response are also explored. Therefore, this research delves into the exciting potential of combining cork-based multilayer structures with strategically integrated shear thickening fluids to develop innovative configurations for bolstered impact resistance. Through rigorous low-energy impact tests using a hemispherical impactor, the experimental investigations reveal promising configurations within the cork-based sandwich structures that dramatically decrease impact forces. Notably, strategically incorporating shear thickening fluids between cork layers is critical in achieving substantial reductions in impact forces. Remarkably, the presence of these fluids slows down the force increase rate during critical displacement periods, offering valuable insights into the impact mitigation mechanics of these hybrid materials. Furthermore, extrapolating from these findings, the study suggests that the increase of shear thickening fluid amount could offer further enhancements in performance within such applications, potentially broadening the scope of impact-resistant materials in protective equipment and related domains.