Rigid Polyurethane Foam as an Energy Absorbing Core for Composite Components Manufactured by Resin Transfer Moulding (RTM) Part II: Prediction of Properties and Validation of Constitutive Models

Abstract

Foam constitutive models allow the effects of changes in parmeter such as density to be predicted and can be used to generat input data for non-linear finite element models. This paper considers three approaches to the constitutive modelling of rigid polyurethane foams: (i) an empirically based shape function approach, (ii) an approach based on a consideration of the mechanics involved in the deformation of a unit cell and (iii) the construction of representative mechanical analogue models. Each approach considered in term of its accuracy, general applicability and ease of use. It is found that the three methods vary primarily in their reliance on experimentaI data and that this directly influences their levels of accuracy. The choice of approach is therefore largely dictated by the availability of appropriate test data.