An SMA Seal System for Enhanced Door Soundproof Performance: Design, Prototyping and Testing

The present work, developed within the National Project "New Technologies and Materials for Vehicle Noise Abatement", LowNoise, focuses on a system able to improve the car door adhesion level in cruise condition, through a SMA based expanding system, integrated within the seal socket. The SMA is activated only in cruise, while is turned off during door lock operations. Moving from the industrial requirements, the specifications of the system have been generated. Through a trade off, a radially expanding cell-system activated by a SMA wire has been selected. Features (dimensions, geometry, materials) and performance (radial force, power consumption) have been assessed through a dedicated modelling. In the subsequent prototyping task, SMA-cell interfaces have been defined. The cell has been mechanically characterized, then installed onto the reference car, and finally tested within an anechoic chamber. The results have proved the system ability to guaranteeing the required acoustic insulation within the entire operational scenario.