Long-term Tensile and Compressive Behavior of Polymer Foams

Abstract

Polymeric rigid foams are increasingly used for highly loaded mechanical applications, e.g., as core in foam sandwich constructions in aircraft or automotive parts. So far the mechanical behavior of rigid foams is not determined precisely. Therefore, the core of sandwich constructions is not taken into consideration for the mechanical design. This leads to oversizing and extended material consumption. This article presents experimental results of long-term tests and indicates a theory to take into account the difference of tensile and compressive behavior of foams. This theory is based on a strength hypothesis and can be implemented in commercial finite element programs. The proposed method leads to an improved mechanical design and, as a consequence, a reduction in mass of construction parts.