Correlative digital image correlation and infrared thermography measurements for the investigation of the mesoscopic deformation behaviour of foams
Abstract
Open-cell metal/polymer hybrid foams are biomimetic open-porous composites, consisting of a polymeric foam electrochemically coated with a metallic layer. Due to their specific pore structure, they can be used in lightweight applications or as crash absorbers. The nanocrystalline coating leads to a strengthening effect and largely improved energy absorption capacity. Understanding the mesoscopic deformation behaviour of foams is essential for the design of intelligent and safe crash absorbers for the future. The present contribution focuses on the full-field thermomechanical analysis of the mesoscopic deformation of metal/polyurethane hybrid foams and hollow strut foams. Local strain fields from digital image correlation were directly coupled with local temperature fields from infrared thermography. A new software tool allows for the direct correlation of thermal and mechanical fields and for the corresponding experimental stress-strain data. Furthermore, the evolution of the energy absorption capacity as function of the strain rate was determined using infrared thermography.