Dynamic reflected waves experimental measurements to characterize the nonlinear elastic properties of sandstones

Abstract Studies on the nonlinear elasticity of rocks offer a promising new method for enhancing resolution rates in field exploration. With transmitted waves or surface waves, numerous laboratory experiments have been conducted to investigate the nonlinear elastic properties of various materials across different research domains, such as fatigue cracked steel in nondestructive testing, trabecular bone porosity in medical imaging or different sorts of earth materials in geophysics. Based on the theory of transmitted waves, the application of rock nonlinear elasticity has been integrated with background noise imaging for field exploration. Reflected waves have a wide range of applications in various exploration fields. However, there have been no experiments or field studies that corporate nonlinear elasticity of rocks into reflected wave exploration. To broaden the application of nonlinear elastic experiments in field settings, we first utilize reflected waves instead of transmitted or surface waves to assess the nonlinear elasticity of rocks. In our experiments, we tested samples of Crab Orchard Sandstone and Lucite. By comparing the variations in elastic modulus as a function of strain for both materials, we observed pronounced nonlinear elastic behaviors in the sandstone sample. In contrast to experiments employing transmitted waves, our utilizing reflected waves experiment yielded comparable results in revealing the nonlinear elasticity of the rock. Notably, there has been no prior research using reflected waves to investigate the nonlinear elasticity of rocks at both the laboratory and field exploration scales. Our innovative approach may serve as an in-situ method for addressing challenges in single well logging or seismic exploration.