Publications Details

Development and validation of a viscoelastic foam model for encapsulated components

Hinnerichs, Terry D.; Urbina, Angel U.; Paez, Thomas L.; O'Gorman, Christian C.

Accurate material models are fundamental to predictive structural finite element models. Because potting foams are routinely used to mitigate shock and vibration of encapsulated components in mechanical systems, accurate material models of foams are needed. A linear-viscoelastic foam constitutive model has been developed to represent the foam's stiffness and damping throughout an application space defined by temperature, strain rate or frequency and strain level. Validation of this linear-viscoelastic model, which is integrated into the Saunas structural dynamics code, is achieved by modeling and testing a series of structural geometries of increasing complexity that have been designed to ensure sensitivity to material parameters. Both experimental and analytical uncertainties are being quantified to ensure the fair assessment of model validity. Quantitative model validation metrics are being developed to provide a means of comparison for analytical model predictions to observations made in the experiments. This paper is one of several parallel papers documenting the validation process for simple to complex structures with foam encapsulated components. This paper will describe the development of a linear-viscoelastic constitutive model for EF-AR20 epoxy foam with density, modulus, and damping uncertainties and apply the model to the simplest of the series of foam/component structural geometries for the calibration and validation of the constitutive model.