Investigation of modulus matrix changes of drained sand in monotonic loading and its numerical analysis

The primary purpose of studying the behavior of sand is to calculate its deformation at loading. The granular structure of the sand causes the transfer of forces through multiple contacts of the particles. Its deformation results from the combination of slip and roll of the particles. Accordingly, changes in the sand modulus matrix are observed considered in this research. The studies show that by assuming different spring behavior in each loading increment for the set of sand particles, a numerical linear-nonlinear behavior can be defined according to the drained experimental results. Therefore, proportional numerical functions are defined based on the trend of changes in modulus of elasticity and changes in the Poisson ratio of sand during monotonic loading. The coefficients are obtained from the related experimental results. The computational effects of these functions in the process of the analytical method are used to convert the experimental behavior of sand into a numerical behavior. The validity of this numerical method is based on calibration and comparison with valid experimental results. In addition to hardening behavior, this numerical analysis can define softening behavior.

Keywords:

sand , modulus matrix , damage , drained , monotonic loading , numerical method , softening