TY - JOUR
TI - Cracking characteristics of granite under different laser powers
AU - Yang Lei
AU - Xie Jing
AU - Liu Jun-Jun
AU - Zhou Xue-Min
JN - Thermal Science
PY - 2025
VL - 29
IS - 2
SP - 1313
EP - 1317
PT - Article
AB - This article explores the crack characteristics and crack propagation laws of  granite under different laser power conditions. Research has shown that  high energy lasers induce the generation and propagation of cracks in  granite by generating local thermal stress. The experimental research object  is granite, and the evolution of crack characteristics is observed by  irradiating with five laser powers of 250 W, 500 W, 750 W, 1000 W, and 1250  W for 30 seconds. Research has found that as the laser power increases, the  crack opening on the granite end face and the diameter of the central melt  hole gradually increase. Cracks are distributed radially symmetrically, and  transverse through cracks appear when the power is greater than or equal to  750 W, forming small fragments. The side cracks are distributed in a "human"  shape, and the depth of the cracks is basically not affected by the laser  power, but the opening increases with the increase of power, and the  transverse branching cracks gradually appear. The local heating caused by  laser irradiation leads to uneven thermal expansion, resulting in  significant thermal stress. When the stress exceeds the strength of the  rock, cracks are induced. This study provides a theoretical basis and  scientific foundation for the application of laser assisted rock breaking  technology in deep resource exploitation and complex engineering.