Abstract
The effects of temperature on the fatigue behavior of foam core sandwich structures have been investigated. Two types of PVC cores of the same nominal density were used; one was linear HD foam and the other a slightly cross-linked H foam. In both cases the face sheet material was S2-glass/vinylester. Fatigue tests were conducted on these sandwich structures at room temperature (RT), 40° and 80 °C. The tests were conducted on an MTS machine equipped with an environmental chamber. The stress ratio was set at R=0.1 and the frequency, f=3Hz. S-N diagrams were generated and revealed that fatigue life increased with decreased stress and decreased with increased temperatures. At RT, HD structures revealed much longer fatigue life compared to H structures however at elevated temperatures, a complete reversal of this trend was seen. Further, significant differences in the failure between H and HD structures were observed. Details of the experimentation, the analysis of the fatigue data, and damage mechanisms are presented.