<title>Shear measurements of viscoelastic damping materials embedded in composite plates</title>

Embedding viscoelastic damping materials into graphite/epoxy composites can greatly increase the damping of composite structures. Cocuring the damping material with the composite, however, has been shown to increase the modulus and lower the damping in many viscoelastic materials because epoxy penetrates many damping materials (especially acrylics). In this paper, the changes in shear modulus were measured using double lap shear tests. Also presented are shear moduli comparisons of samples cured with three different barrier film layers, KaptonR, TedlarR,and polyester, which are used to prevent the epoxy penetration. Lastly, samples with an embedded loosely woven scrim cloth placed between two damping material layers are tested to measure how the scrim affects the shear modulus.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.