Analysis and design tools for structures damped by viscoelastic materials

Abstract

Constrained viscoelastic layers have traditionally been considered as damping enhancement mechanisms. More recently bonding has appeared as an alternative to traditional welding strategies and sandwich shells with thick plastic cores have been considered to provide high flexural stiffness for a low overall weight. The present study focuses on computational strategies that can be used to analyze and design the vibroacoustic behavior of such assemblies. Difficulties of the task are the use of experimentally derived complex moduli for the viscoelastic materials, studies in the frequency and temperature domains, integration of the bonded shells into large finite element models, ability to modify the geometry of a particular assembly in an optimization phase or the ability to account for changes in the viscoelastic material properties during the part forming process. The study is illustrated by applications to an automotive oil pan.