Mesoscopic hysteretic model and parameter study on cemented sand and gravel material

According to the hysteresis loop characteristics of the cemented sand and gravel (CSG) material under an equal amplitude cyclic loading test, taking into account the influence of cycle times and plastic residual strain, a plastic mesoscopic hysteretic model of the CSG material was established based on the theoretical Preisach-Mayergoyz model. The sensitivity of the mechanical characteristics corresponding to the shape parameters, the fatigue life (frequency), the total number of hysteretic mesoscopic elastic units (HMEU), and the size of the load step in the model was analyzed. The results showed that the shape parameters mainly affect the form of the hysteresis loop curves in the loading and unloading sections, the total amount of HUEU affects the accuracy of expressing the mechanical properties of CSG materials, and the load step affects the fitting accuracy of the hysteresis loop curves. Based on the parameter analysis, the theoretical range of the mesoscopic parameters suitable for the mesoscopic hysteretic model of CSG are shown that, the shape parameter ξ is 1.2-3.0 and η is less than 0.3, the total number of HMEU is 500-10000, the load step should not be significant when its value is greater than 0.08 MPa. The mesoscopic hysteretic model of CSG can also predict the fatigue life of CSG materials under constant amplitude cyclic loading. The research results can provide a theoretical basis for the dynamic characteristics and fatigue failure analysis of CSG materials.