Automated experimental platform and mechanics testing of rock breaking using different lasers

Abstract

Addressing the challenge of breaking rocks deep within the earth requires innovative solutions, and the pulsed laser technology has emerged as a promising noncontact alternative for rock breaking. We developed an automated experimental platform with robotic arms and a rock mechanics testing device to quantitatively study the impact of laser technology on rock breaking. Our investigation delved into the damage caused to rocks by different types of lasers, focusing on understanding their underlying damage mechanisms. Pulsed lasers, excluding thermal effects, reduced the red sandstone strength by 68.07%, with a decrease in peak tensile force by 30–33 N per 1000 pulses. Furthermore, we conducted detailed quantitative analyses to understand how laser power (P), irradiation duration, and output energy affeted rock damage. Increasing laser power or irradiation duration enhanced rock damage since this increased the laser output energy. For every 100.00 W power increase, the peak force decreased by 51.00–88.00 N, and for every 1000.00 ms duration increase, the peak force decreased by 34.00–42.00 N. Maintaining constant output energy while changing the laser power revealed a quadratic nonlinearity in peak force, aiding in determining optimal laser parameters. This study highlights the potential of laser technology for effective rock fracturing during deep earth exploration. The established experimental platform improves the accuracy and reliability of laser-induced rock breaking, offering insights for future advancements in this field.

Keywords

• pulsed laser
• rock mechanics testing
• laser-induced rock damage
• experimental equipment
• mechanical damage
• quantitative analysis