Structure dynamic study of noise encapsulations

Sammanfattning: This report is the result of a study performed as a master thesis. The study involves different noise encapsulations intended for Scania trucks. The work was performed at the Marcus Wallenberg Laboratory for Sound and Vibration Research, MWL. The study consists of two parts. The first part is a comparison survey concerning the sound reduction qualities of different types of noise encapsulations. The second part is a modal survey of the standard noise encapsulation currently employed by Scania. The report is divided into two chapters each treating one of the surveys. Both chapters start with a short theoretical deduction and description of the method that is being used. Thereafter follows a practical description of how the survey was executed. The main results are given last in each chapter.