Macroscopic failure of multilayered viscoelastic polymers

This study considers creep deformation (macroscopic failure) of laminated polymer materials. A closed form analytical model is developed to characterize creep in laminates loaded in the linear viscoelastic region. For nonlinear viscoelastic loading, a numerical solution is developed. The models are based on an application of laminated plate theory to materials with viscoelastic layers. Both approaches are able to predict laminate behavior with input of appropriate material properties for each layer. Experimental data are presented, which confirm the validity of the analytical model for laminates constructed from nylon66 and liquid crystalline polymer films. The validated macroscale failure models are capable of characterizing a variety of materials. A case study is included to demonstrate the influence of layer properties and orientation on overall laminate performance.