## 1 Introduction
[PERSON], [PERSON] et al. [22] and [PERSON], [PERSON] et al. [23] believe that the proportion and number of crack types are greatly affected by the strength of the rock and verified the feasibility of the RA-AF qualitative evaluation model for the evolution of rock fracture types under cyclic loading. The evolution of rock damage under cyclic loading and unloading is often difficult to express, and the energy dissipation theory is further used to reveal the damage evolution mechanism under cyclic loading and unloading. [PERSON], [PERSON] et al. [24] compared the energy dissipation of graded cyclic loading and unloading and variable lower limit cyclic loading. The study found that the elastic energy, dissipated energy, and total energy of the rock are positively correlated with the number of cycles, and under the variable lower limit cyclic loading and unloading path, rock failure is more severe. [PERSON], [PERSON] et al. [25] established a brittle rock damage variable defined by the ratio of dissipated strain energy to the total strain energy and derived new damage variable characteristics, including the compression energy dissipation coefficient and strain energy parameters. [PERSON], [PERSON] et al. [26] found that the dissipated energy shows a fast-stable-fast-slow-fast growth trend, while the elastic energy index shows a trend of significant increase-stable-increase-decrease. [PERSON], [PERSON] et al. [27] found that the energy density of the rock increases nonlinearly with the increase in axial stress, gradually increasing first and then rapidly increasing. From the current research status on the strength characteristics of rocks under cyclic loading and unloading, as mentioned above, it is evident that studying the deterioration mechanisms of rocks under cyclic loading and unloading is a highly significant topic [28; 29]. Currently, the mechanical characteristics of rock are primarily assessed through uniaxial compression tests, while there is a lack of research on cyclic loading and unloading tests for rock. Many scholars focus solely on analyzing the mechanical properties of rock, with less attention given to the precursors of rock failure and deformation monitoring analysis. This experiment employs AE (acoustic emission) and DIC (digital image correlation) to monitor the changes in AE signals and deformation of the rock under loading from multiple perspectives and analyzes from various angles, including the b-value of acoustic emissions and the Felicity effect. This study, integrating acoustic emission (AE), digital image correlation (DIC) techniques, rock mechanics, and fracture damage mechanics theories, primarily focuses on conducting uniaxial compressive strength tests under cyclic loading and unloading for sandstone with a 45\({}^{\circ}\) fracture inclination. The findings aim to provide guidance for related geotechnical and engineering construction projects. Cyclic loading and unloading tests can assess the mechanical behavior of sandstone in a simulated underground mining process, including its strength, deformation characteristics, and failure modes. The use of AE (acoustic emission) monitoring allows for a deeper understanding of the precursors of rock failure, and high-speed cameras are employed to further monitor the deformation of the rock. The cyclic loading and unloading tests provide response data for sandstone under different stress paths, which can be used to guide the design of mine support structures, such as selecting the appropriate type, size, and layout of support. Moreover, cyclic loading and unloading tests can help to identify potential signs of rock failure, providing a scientific basis for mine safety management and risk assessment.