Damage control characteristics for notched blasting based on the damage mechanism

In this paper, based on the secondary development of the LS-DYNA, a user-defined statistical damage model was implemented.The stress and damage distribution of conventional circle hole and notch hole were compared.Results demonstrate that two mechanical effects are induced by the notch.High stress concentration is generated at the edge of the notch and the stress at the other part of blast hole is reduced.The sensitivity analysis of notch angle and depth were carried out.Results reveal that the most perspective angle is 60°.The threshold value of notch depth exists, while the control effect of damage is not obvious when the depth is bigger than the threshold value.The rock strength affects the selection of the best depth significantly.As the rock strength increases, the depth is larger.The research results of this paper have important engineering application value.