| Abstract: | The through-thickness variation in the porosity of structural foam material is known to result in different “material properties” when mechanics based on homogeneous materials is used to interpret data from standard tensile and bend tests. Unresolved issues relating to structural design include the specification of the most useful test specimen, the identification of useful material properties, and the application of these properties to part design and analysis. This paper develops procedures for determining the mechanical properties of rigid thermoplastic structural foams, and for the application of these properties to the design of load-bearing components. Rather than molded specimens, it is suggested that specimens cut from large, edge-gated plates be used for determining mechanical properties of structural foams. By modeling foams as continuous but nonhomogeneous materials, it is shown that data from simple tensile and flexural tests can be used in structural analysis to systematically account for the through-thickness variation of material properties. |
