IN-PLANE IMPACT FORCES AND BEHAVIOUR OF NATURALLY-BEDDED SLATE MATERIAL DURING IMPACT SPLITTING TESTS

摘要

In this paper the experimental and numerical investigations that were carried out to understand the splitting behavior of naturally bedded layered slate specimens are reported. Material properties of slate were obtained from careful and detailed laboratory experiments carried out for this purpose. The splitting of different sizes of slate blocks was carried out using a wedge-shaped indentor attached to a hydraulic actuator. Splitting load and strain responses were obtained through a data acquisition system using Lab View software. Mode I (plane strain opening mode) dynamic crack propagation was simulated numerically by the sequential releasing of the restraining node on the symmetric plane of the specimens. Predefined impact load scenario was applied to the specimens with an initial crack, and the mode I stress intensity factors were computed for different crack lengths. Stress intensity factors for crack growth between 0.4 to 0.6 times the depth of the specimen were compared with the material fracture toughness obtained from earlier experiments.