Mechanical properties of grain in silos for simulation designs

Abstract

For the calculation of silos structures it has been used new methods and computational tools that require mechanical properties knowledge that are still unknown for most storable materials, especially grains. In this context, we aimed to determine the mechanical properties of rice and beans grains with moisture contents of 10, 12, and 14% by applying four compressive loads (5, 10, 15 and 20). The determined mechanical properties were Poisson's ratio (ν), Modulus of Elasticity (E), and the dilatancy angle (ψ). The procedure consisted in the application of the load in compression cell, adapted from MOLENDA & STASIAK, aiming to simulate loading and unloading of silos. We observed that the Poisson's ratio calculated for both loading and unloading, presented higher values than the experimental values, with the increase of their moisture content; the experimental elastic modulus presented higher values than the calculated ones, and both increased their values with the increase of their moisture content; the dilatancy angle decreased with the increase of moisture content and compressive loads.

The Use of Simulation Software using the Discrete Element Method (DEM) for the Process of Materials Comminution

“…The need for modeling of shredding and flow of bulk materials is mainly due to machine problems occurring during their processing: loss of ability to move (transport) the bulk material by blockage of dosing channels, transporting in feed supply systems, processing processes, too high intermolecular friction, which causes the effect of material clogging, which in consequence leads to material losses or deterioration of the quality of processed, transported material, energy start, decrease in efficiency and effectiveness of processing lines, and thus increase costs [1][2][3][4][5]. Therefore, it seems rational to model and search for structural solutions of machines working with loose materials, taking into account the modeling of the behaviour of these materials in contact with the working surface of these devices.…”

“…Computer applications based on solving problems with the use of numerical methods become helpful in this respect. One of the methods used to solve calculation problems of grinding and flow of bulk materials is the Discrete Elements Method (DEM), which allows to simulate the behavior of materials under machine conditions [1,2,33]. The Discrete Elements Method has recently been one of the most frequently used methods in the analysis and simulation of the flow of bulk, granular materials, supporting the optimization of machine and equipment design.…”

“…The Discrete Elements Method has recently been one of the most frequently used methods in the analysis and simulation of the flow of bulk, granular materials, supporting the optimization of machine and equipment design. Much attention is paid to issues related to modeling of mixing processes [34,35], storage [1] and transport [36] of granular materials and grinding, mainly of brittle materials, e.g. rocks and minerals [37][38][39].…”

Theoretical Studies of the Interaction between Screw Surface and Material in the Mixer

“…The need for theoretical modeling of mixing processes results precisely from the operational problems in the machine mixing and the problems related to the material flow itself in contact with the working elements of the mixers, which include, among others: loss of the mobility of the bulk material due to clogging of the dosing channels in the feed supply systems; too high intermolecular friction, which causes the effect of clogging of the material, and consequently leads to material losses or deterioration of the quality of the mixing product, and even energy losses and a decrease in the process efficiency and, thus, an increase in costs [ 9 , 18 , 19 , 20 ]. Therefore, it seems rational to model and search for optimal material, process and construction parameters for the bulk materials mixing processes, taking into account the physical basis of the behavior of these materials in contact with the working surface of the mixing devices.…”