Optimizing Bulk Material Handling Through EDEM-OptiStruct Two-way Coupling

PrasadAvilala · May 9

In the field of mechanical engineering, different equipment is designed to handle bulk materials. Discrete element method (DEM) and Finite element method (FEM) are two numerical methods available for researchers and engineers to develop new products and address complex engineering problems. These two methods have their advantages, respectively.

EDEM is a high-performance software for bulk material simulation, and it is powered by Discrete Element Method also known as DEM.

EDEM simulates and analyses the behaviour of granular materials such as coal, mined ores, soil, grains and powders – and their interaction and impact on machinery and equipment

OptiStruct Explicit is a nonlinear explicit finite element analysis (FEA) that solves dynamic problems with time-dependent solutions. It uses the explicit time integration method, which is based on the central difference scheme, to calculate the structure's behavior over time. This approach is particularly well-suited for simulating fast, highly nonlinear events like crashes, explosions, and other situations involving large deformations and strain rates.

Why EDEM-OptiStruct(OS) 2-Way Coupling?

Numerous practical problems are not just a discrete or continuous problem but a combination of these two intractable issues. Therefore, a combined DEM–FEM numerical method was developed to solve realistic problems and optimize the structures.

DEM and FEA coupling allows us to predict

Large geometry deformations
Stress/Strain
Durability of the structure

https://youtu.be/IGC6XKBM4nc

Benefits of Using EDEM -OS Two Way Coupling

Some of the benefits of using EDEM with Finite Element Analysis are

Realistic structural analysis based on EDEM bulk material data. This provides users with results of on-site performance, rather than having a hydrostatic loading which cannot reflect what the actual loadings are like in the real scenario
Optimize equipment design based on interaction with bulk material
Greater insight into equipment performance

EDEM- OS coupling schema:

EDEM-OS 2-way data exchange is as follows

OptiStruct-EDEM coupling allows the advanced structural analysis capabilities of OptiStruct with bulk and granular material interaction capabilities of EDEM. You can simulate and analyze the interaction of materials such as coal, soils, grains, and so on with deformable surfaces. It is currently only supported with Explicit Dynamic Analysis (NLEXPL) subcases.
OptiStruct transmits nodal coordinates and velocity to EDEM, while EDEM sends nodal forces to OptiStruct during the coupling, which occurs at each synchronization point after a time defined as the coupling time-step specified by the PERIOD field.

Co-simulation starts at time (t)= 0 sec to t= Termination time (Tterm)

The Forces applied by OS on coupling nodes are linearly ramped in a coupling period [tn + DT; tn + 2DT ] from Ftn to Ftn+DT

Key Points to be Noted:

The following points to be noted while setting up EDEM- OS two-way coupling:

Ensure that the Unit Systems defined in both OptiStruct and EDEM are consistent. For OptiStruct-EDEM coupling runs, it is mandatory in OptiStruct to define the UNITS Subcase Entry to identify the model units. It is your responsibility to make sure that this identified unit's system is consistent with the unit's system defined in EDEM.

The coupling interface surface is defined only in OptiStruct and the first equipment material data defined in the EDEM model is used as the material data for all coupling surfaces defined by OptiStruct. The coupling surface(s) defined by OptiStruct are exported to the EDEM model during the initialization of coupling. Additionally, the particle type, material, interaction physics data should be defined in the EDEM model.

Summary:

Explore the powerful capabilities of EDEM–OptiStruct two-way coupling and see how you can make the most of both Altair Tools by combining advanced bulk material simulation with high-fidelity structural analysis, you can improve equipment performance. For more information and practical examples, visit the Altair Community.