Damage evolution in sandwich components at different extreme temperatures.

Composites' structures are subjected to various environmental conditions during their service life. However, only a few papers are focalized on analysing damage history after impact at shallow temperatures and among them, even less concern sandwich components. Futhermore, since the effect of any degradation phenomena may not be visible to the naked eye, the evolution of the damage is followed with non-destructive techniquest. In this paper, the damage suffered by sandwich structure composites was evaluated by three NDT techniques: Ultrasound, Lock-in Thermography and speckle interferometry. Sandwich structures investigated consist of carbon fibre reinforced face sheets surrounding a PVC core. Indentation and penetration tests (U = 7.5J, 10.5 J and 12 J) were carried out at room temperature and −55°C, +70°C. After tests, damage extension and propagation has been evaluated in terms of indentation depth and delamination by NDT. The results provided useful information about the influence of extreme temperature on both impact properties and damage evolution in the system investigated. [ABSTRACT FROM AUTHOR]