Customization

Rocky DEM’s Application Programming Interface (API) is based on the most-recent technology for customization and user experience integration. This combination provides unique usability, portability and, above all, solver performance. Rocky allows you to customize the application interface, using the Pre & Post API, and to compute advanced custom models using the Solver API.

Pre and Post-API

Scripting API is a great way to save time by automating repeatable tasks. Scripting gives access to Rocky DEM raw data and simulation results, so you can automate your case setup and post-processing steps, especially when you’re performing a complex analysis for many similar kinds of cases. The API can configure and simulate a project from scratch, analyze and export simulation results, and perform computations that go beyond Rocky’s standard feature set.

Ready-to-use functional scripts are available in the Rocky Customer Portal, for users to download.

C++ Solver API

The Solver API is C++ based, and it enables physics such as:

• Contact models
• Joint models (for flexible particles)
• Body forces
• Particle properties and custom scalars
• Instantaneous and Discrete Breakage
• Impact energy
• CFD coupling laws (drag, lift, torque, virtual mass and heat transfer)
• Wear geometry modification

It gives access to the simulation processing cycle, making it possible to select a specific processing to include a custom code to compute on the solver time. This lets you implement a completely new model to execute on Rocky.
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User Experience

A seamless deployment of custom models, backed by a visual interface in the setup stage, and all new custom variables automatically available for detailed analysis in the post-processing stage.

Single Code For Both Multi-CPU & Multi-GPU Solvers

One single code compatible with both solver technologies, reducing the cost of maintaining custom routines or learning complex GPU programming techniques.

No Performance Degradation

Users can implement custom models using the same structure and logics from embedded models without code virtualization or memory overhead.

Modules available for download

40+ Functional ready-to-use examples are available on the Rocky Customer Portal. Users can download and use them immediately or they can be changed/extended as per user needs (source code available).

Material Wizard

Material Wizard dovetails into Rocky’s calibration suite and is designed to jump-start Rocky simulations by turning real-world material information into ready-to-use setup parameters. The Wizard compares experimental data with a built-in material database and uses AI/ML techniques to provide the best required material-related simulation parameters.

Multibody Dynamics

Rocky DEM allows you the freedom to configure complex geometry movements by enabling many translations, rotation, vibration, swinging, crushing, and free-body motions as you need.

Moreover, Rocky’s fully integrated motion kernel offers support for combined geometry motions right within the software – no need for any third-party motion tools.

So whether you want to prescribe exact movements, or have your geometry components move freely in response to outside forces like particle contacts and gravity, Rocky DEM has your complex motion needs covered.

For more complex multibody motion models, Rocky has 2-way coupling with the Ansys Motion tool. See below the new possibilities with this coupling.

Possible Movements

• Translation
• Rotation
• Periodic Rotation (Pendulum)
• Periodic Translation (Vibration)
• Free Body Translation
• Free Body Rotation
• Additional Force
• Additional Moment
• Spring-Dashpot Force
• Spring-Dashpot Moment

Create Complex Movements

• Combined Motion
• Nested Frame

New possibilities with Ansys Motion coupling

• Complex nested and chained motions
• Stress and deformation of flexible body components
• Geometry-to-Geometry Interaction
• Advanced Mechanisms Logics and Behaviors (PLC, Matlab, …)

Multi-GPU Processing

The multi-GPU solver in Rocky DEM distributes and manages the combined memory of two or more GPU cards within a single motherboard, overcoming memory limitations and achieving a substantial performance increase by aggregating computing power. Regardless of the size of your business, Rocky can speed up your particle simulations.

Rocky’s Benefits

Rocky can help you:

• Facilitate large-scale simulations involving tens of millions of particles and/or complicated solutions.
• Speed up computational time and simulation performance.
• Scale down additional CPU memory costs.
• Reduce energy consumption.
• Free-up all your CPUs for coupled simulations, avoiding hardware competition.

Performance Benchmark

A performance benchmark for a rotating drum illustrates how Rocky’s multi-GPU solver speeds up solve time in many common applications. For more info, check our blog. 

Performance

Besides Multi-GPU Processing and continuous memory consumption optimization, Rocky has a Multi-Zone Dynamic Domain technology.

It enables faster simulation, making it possible to simulate applications with several millions of particles by both reducing memory requirements and speeding computational time. This simulation optimization methodology enables dynamic calculation zones of interest to include or minimize contact detection inside or outside of the zones, based on where the particles are active.  For example, the simulation of disk harrow equipment (shown below) was accelerated by 9x using the new dynamic simulation domain capability.

Performance is paramount for Rocky, and recently it launched the brand new Particle Assembly shape type, whose main goal is to increase computational efficiency by combining simpler particles’ shapes to replace more computationally expensive ones.

In the case shown below, it achieved a performance 36x faster with 22x less memory consumption.

Breakage Modeling

Regardless of the particle shape or the application being analyzed, Rocky DEM has the
appropriate breakage model for you. All models can preserve the mass and volume of the original particle.

Instantaneous Fragmentation

The Ab-T10 and the Tavares models allow the representation of hard materials’ brittle breakage, producing randomly shaped fragments with smaller fragments being generated closer to the impact point.

Ab-T10 Breakage Model

Rocky DEM works with both a fracture subdivision algorithm and a breakage energy probability function, which itself is based upon a well-established model in the industry (JKMRC Ab-T10). This breakage model uses arbitrary-shaped convex polyhedrons and can preserve both mass and volume during the breakage process. Also, it treats every particle as a single entity that can be broken into fragments instantaneously based upon the breakage force and/or energy values defined.

Tavares Breakage Model

The Tavares breakage model is an extension of Rocky DEM’s original Ab-T10 breakage model. It has been validated via single-particle testing, and the results have been documented in many peer-reviewed publications over the last 20 years.

This model focuses on fracture by low-energy stressing, which helps in simulating many unit operations in particulate materials processing and handling, where particles are often subject to a complex series of loading events.

Tavares’s breakage model describes the progressive growth of crack-like damage that ultimately leads to the fracture of a particle under stresses significantly lower than those required for breakage in a first event.

Discrete breakage

Rocky’s unique discrete breakage model is a high-fidelity model that considers the collision location at the particle’s surface along with its consequent internal stresses, capturing shape-dependent breakage and crack propagation.
Unlike most DEM codes that use a combination of spheres connected to each other to approximate a particle shape, Rocky uses tetrahedrons, allowing for representation of any particle shape, preserving volume and mass. Thus, it can simulate breakage for particles of any shape and aspect ratio: fibers, shells, and custom shaped particles.

3D Surface Wear Modification

Rocky DEM can be used as a tool for predicting the abrasive wear of solid surfaces. In addition, Rocky implements a validated Archard’s wear model, providing an accelerated wear model so that months of wear patterns observed in the field can be predicted after a few minutes of virtual simulation.

The transient variation of normal and shear stresses on the surface and their related work are computed accurately and viewed easily.

There are two major ways you can use Rocky to gain an understanding of how your geometries will wear over time:

•  Enabling wear surface modification, which changes the physical appearance of the geometry as the simulation progresses.
• View a color map of the surface intensity.

Collision Statistics

The visualization of collision statistics is a key feature in Rocky DEM.

Intra-particle Collision Statistics

For certain solid and flexible particle sets, you can obtain collision data between two consecutive output time levels. This data can be displayed graphically on the surface of a representative particle, using a conventional field representation with a color scale. You can then differentiate performance for different particle types subject to the same process, or evaluate surface wear and particle chipping.

Inter-particle Collision Statistics

If you want to expand the set of particle properties available for post-processing, including several statistical properties that may be collected during a simulation, you can collect Inter-particle Collision Statistics before processing your simulation. This can be useful when you need to extract data that considers all collisions that happened to a certain particle between two output periods. For example, with impact velocity, you could relate that data to the chances of the particle breaking or causing it to deagglomerate. With duration, you could relate that data to a certain mass or heat transfer process, or to a certain chemical reaction.