An experimental and computational study of the crushing of metallic hemispherical shells between two rigid flat platens

The axial compression of aluminium spherical shells with a ratio of mean radius to wall thickness ranging from 15 to 50 was carried out between two rigid flat parallel platens. Quasi-static tests were conducted on an Instron machine (model 1197) of 50 t capacity. Spherical shells of different radius and thickness were tested in order to identify their collapse modes and to study the associated energy absorption capacity In experiments, all shells were found to collapse owing to the formation of inward dimpling associated with a rolling plastic hinge. The deformation of the shells was also studied and analysed with the help of the finite element code FORGE2. Predicted variations in different components of strain and stress are presented. Experimental and computed results are compared. Some of the obtained results are also compared with the solutions proposed in earlier studies. On the basis of the findings of the experiments and computational model, the basic mechanism of deformation of shells is presented and discussed.