Effects of dip angle and length of open joints on dynamic properties of materials like rock

In order to investigate the influence of tensioned joints on the dynamic mechanical properties of rock-like materials under impact loading, investigated the stress wave propagation characteristics, peak bearing capacity, damage pattern and damage law based on energy theory under dynamic loading for intact specimens and cement mortar specimens containing joints of different angles and lengths with the help of a split Hopkinson compression bar device.The results show that the specimens will be damaged by forming a set of tensile cracking surfaces along the axial direction through the joint surface and a set of cracking surfaces almost parallel to the end face of the specimen.Under the experimental loading rate, when the joint length increases from 5 mm to 30 mm, the more obvious the reflection effect on the wave, the smaller the peak bearing capacity of the specimen, and the smaller the damage.When the joint angle increases from 0° to 90°, the smaller the reflection effect on the stress wave, and the smaller the damage value of the specimen.The peak bearing capacity of the specimen decreases with the increase of the joint angle and then increases.When the joint angle is 60°, the peak bearing capacity of the specimen reaches the minimum, and when the joint angle is 90°, the peak bearing capacity of the specimen reaches the maximum.