SMC/TPE bi‐layer configurations for structural vibration damping applications

Sheet molding compounds (SMCs) have considerable potential as lightweight alternative to traditional materials used in automotive components. However, despite their outstanding mechanical properties, their vibration damping characteristics are often relatively poor for several applications. Therefore, enhancing the vibration damping capability of SMCs represents a field with increasing interest. Application of viscoelastic layers to high stiffness materials, such as SMCs, represents an effective approach to add vibration damping functionalities to lightweight structural components. In this work, the incorporation of thermoplastic elastomers (TPEs) is studied as a novel strategy to enhance the structural vibration damping capability of SMCs. Several types of SMC and TPEs have been considered and the effect of TPE-SMC thickness ratio on the damping and stiffness properties is investigated. The viscoelastic properties and vibration damping performance were evaluated by dynamic mechanical analysis. The effect of TPE addition on stiffness was studied by three-point bending. Results reveal the potential of the incorporation of thin TPE layers as cost-effective strategy to enlarge the vibration damping efficiency of SMCs while maintaining their overall high stiffness. It is expected that the bi-material configurations presented in the current study will contribute to advance the development of new lightweight multi-functional solutions for modern transport applications.