Modeling the compressive fracture behavior of foams for energy absorption

Polymeric foams and foams in general have a wide variety of applications ranging from energy absorption, noise and vibration absorption, and thermal insulation. In some segments of transportation applications, foams are used specifically for energy absorption during a vehicle crash. These foams are designed for one-time use to protect vehicle occupants where recoverability of the foam is not prescribed. Recently, it has been identified that a square-wave load versus displacement response is desired for these applications. Observations of foam crushing during compression have demonstrated the need for an appropriate phenomenological model for foam failure. Current foam-structure-property models do not go all the way to final failure and can predict the early stage of load-displacement relationship. But, in terms of energy absorption, the model which covers the extensive load-displacement relationship is very important. This article will detail the development of a structure-property model used throughout the development of a new family of lightweight, space efficient, energy absorbing foams.