Mechanical properties and forming behaviour of laminated steel/polymer sandwich systems with local inlays - Part 1

摘要

Steel/polymer/steel sandwich materials (SMs) with varying core thickness were produced using the roll bonding technology. At constant skin thickness, the effect of the core thickness change on the mechanical properties, particularly their specific stiffness and strength, was investigated. Additionally, the SMs were locally reinforced with steel inlays to improve their behaviour against dimension changes or the degradation of the core in case of local loading or joining. The effect of the reinforcement (RE) on the strain distribution under deep drawing conditions was studied. Strains were measured using photogrammetry. To take into account the influence of anisotropy in this sense, an essential anisotropy evaluation was carried out for the SMs to assess their forming behaviour. The results revealed an adequate agreement between the measured mechanical properties of SMs and the estimated values following the rule of mixtures. Up to a core volume fraction of approx. 0.37, the specific stiffness and strength values of the SMs are only slightly reduced compared to the monolithic steel material. The deformation analysis shows a significant influence of the inserted REs on the strain distribution and failure and consequently the position of cracking, occurring at the bottom/edge region in front of the RE.