Influence of core and face sheet materials on quasi-static and fatigue properties and failure in aluminium foam sandwich

The properties of aluminium foam sandwich materials (AFS) have been studied under static and cyclic loads. Two sandwich variants have been compared, namely AlMnl face sheets/AlSi7 core and AA6060 face sheets/AlSi6Cu6 core. Under static three- and four-point bending, mainly two failure modes occurred: buckling of the face sheet in the region of compressive stresses and shear failure of the core between the outer load introduction points. Within the natural scatter of the material properties, these failures could be correlated with the local stresses and the local strength of the materials. The local mechanical properties had been evaluated by compression experiments on the core materials and tensile tests on the sheet materials. Failure charts have been derived which indicate configurations and local stresses associated with failure mechanisms. The local mechanical properties have been introduced in a weakestlink approach that describes the probability of different failure modes as a function of the local stresses. This approach includes the scatter of the material properties and is able to transfer it to the scatter of the failure modes. Fourpoint bending was also performed in fatigue experiments. Fatigue stresses as well as fatigue failure mechanisms of these experiments are contrasted to the results of the quasistatic experiments. Entnommen aus TEMA