Effect of specimen shape on the behavior of brittle materials using probabilistic and deterministic methods

The main objective of this paper is to verify the activated defect localization under various loading rates for Modified Brazilian Disk (MBD) compared with spherical glass specimen frequently used in the literature. The geometry of specimen can considerably influence the mechanical response of material specially, the brittle materials which are very sensitive to the defects activations and finally corresponding Weibull statistic problematic for these materials. The high and low loading rates have been investigated using universal Instron machine compression and Compressive Hopkinson Pressures Bars (CHPB) on MBD lead glass specimen and then the experimental results have been compared via the Weibull's distribution for scatter strength variation. Finally, we observed the contact problem leading to the activated defects in this area on spherical glass specimen under static and dynamic loading not MBD specimen under both loading rates. Consequently, the probabilistic approach should be taken into account including the specimen geometry and also 'Type' of loading application due to the activated defect position arising from the sever contact problem for the brittle materials.