Flow liquefaction instability and the permissible range of fractional order of sand

To capture the state-dependent behaviour of granular soil, an interdisciplinary approach, fractional plasticity, was proposed. However, the permissible value of the fractional-derivative order has not been evaluated. This technical note aims to analyse the permissible range of fractional order from the perspective of modelling flow liquefaction of sand. A state-dependent fractional elastoplastic model without using predefined state parameters is proposed. Then, a series of test results of different sands under flow liquefactions are simulated. Permissible range of the fractional order is analysed by evaluating the second-order work for predicting flow liquefaction instability of sand, where it is suggested that the fractional order should be less than two.

Automated summary

This technical note analyzes the permissible range of fractional order in modeling flow liquefaction of sand. The authors propose a state-dependent fractional elastoplastic model without predefined state parameters and simulate a series of test results for different sands under flow liquefaction. The permissible range of the fractional order is analyzed by evaluating the second-order work for predicting flow liquefaction instability of sand, suggesting that the fractional order should be less than two.