Simulation Study on Effective Work and Non-coupling Coefficients of Elliptic Bipolar Linear Shaped Charge for Smooth Blasting

Abstract:

Numerical simulation was done on the elliptic bipolar linear shaped charge (EBLSC) based on dynamics simulation software AUTODYN. First, through two-dimensional planar symmetric method and considering granite characteristics, air sandwich and decouple condition, the effects of EBLSC structure and decouple coefficient for smooth blasting were studied. Then, the effective volume work model was established to evaluate blasting results. The results indicated that the specific impulses on blasthole line connecting direction and in vertical direction were similar with deviation below 10%, so the whole energy of charge uniformly was distributed along the circumferential direction approximately. However, there were obvious penetration cracks in blasthole connecting direction with lower crushing and expanding degree of the rock. It indicated that EBLSC could improve significantly the charge energy efficiency and blasting result. In addition, with the decouple coefficient increasing, the loss or waste volume work in blasthole connection direction first decreased and then increased with the existence of maximum effective power. Through curve fitting, the optimal decouple coefficient of about 3.62 was obtained, which was similar to the result of relevant experiments.