Modeling a Flexible Ring Net with the Discrete Element Method

Flexible barriers have been proven to be effective measures for mitigating natural hazards, such as rockfalls, gravel flows, and debris flows. This paper presents a new numerical ring model based on the discrete element method (DEM) to simulate a flexible ring net. The Edinburgh Bonded Particle Model is applied to create internal forces within a ring element. The mechanical behavior of a ring element was analyzed from measurements collected during quasi-static tensile tests. The systematic calibration approach of this ring model is described in detail. Two reduction factors related to the bond Young's modulus and the bond radius are proposed to effectively adjust the bending and axial stiffnesses of the ring element. With calibrated DEM parameters from the tensile tests, the ring model is validated by reproducing these tensile tests under different boundary conditions. Finally, a three-dimensional DEM model is established for modeling the rockfall impact on a flexible ring net. A comparison between the existing test data and simulation results reveals that the new ring model can accurately reproduce the response of a flexible ring net under both static and dynamic conditions.