Ansys LS-Dyna: Workflow Overview

May 25, 2023 Conrad Magalis

Ansys LS-DYNA is the industry-leading explicit software used to simulate a material’s response to short periods of severe loading. 

While it is mostly known for its explicit capabilities, LS-DYNA also offers a large range of other capabilities, including implicit, thermal, forming, element-free methods, linear dynamics, and more.

Engineers in multiple industries leverage the many elements, contact formulations, material models, and other controls in this physics-based tool to simulate a much wider range of applications than possible with other packages, including:

  • Drops
  • Bird strikes
  • Impacts
  • Explosions
  • Crashworthiness
  • Occupant safety
  • Airbag effectiveness
  • Splashing/sloshing
  • Sports equipment

As a Multiphysics solver, it can perform simulation activities across any combination of thermal, electromagnetic, mechanical, particle, and fluid. For example, when testing FSI (fluid structure interaction) problems without LS-DYNA, two programs have to talk to each other in between simulation steps. With LS-DYNA, everything is done within one software that solves the problem with a single code instead of two different programs.

Workflow Components

There are three components to this workflow:

  1. Preprocessor – An input deck to generate the data/files to be fed into the solver
  2. Solver – Performs the analysis
  3. Postprocesses – Reads the files generated by the solver

LS-DYNA is a solver. To be used, a preprocessor and postprocessor are also required. The graphic above shows a few industry standards. At Rand, we recommend Ansys Workbench LS-DYNA, because:

  • It is easy to use
  • Its GUI is similar to Ansys Mechanical
  • It provides additional access to the solver through command objects
  • It creates input decks the solver can read
  • It can post-process the data in the input deck created by LS-DYNA
  • Ansys is continually investing in making the product better 

High-Level Overview of the LS-DYNA Workflow

Below are the main steps of the LS-DYNA workflow. Watch this recorded webinar for details.

  1. Create a content object for every object in your model by entering data into a GUI. In the example below, there is a contact object—an edge contacting a surface. Data about the object is entered into the GUI, as seen below:


     
  2. When information about an object is entered into the LS-DYNA GUI, the system automatically generates a keycard that corresponds to that specific object. This is the basic layout of a keycard:


    The keycard provides functional definitions and descriptions to the solver. For example, in “Contact_Tied_Nodes_To_Surface_Offset
    A) The underscores tell the solver what to look for
    B) “Tied” means it is bonded
    C) “Nodes to Surface” means tying several to a segment
     
  3. LS-DYNA Solver reads the keycards, performs the activities, and sends the results to the post-processor
     
  4. The post processor delivers the results files with data that can be reviewed to ensure the design works as intended

The Case for LS-DYNA

Based on our experience, we know that many people will dismiss this because it seems like too much work. We caution against that dismissal. Yes, it will take time to learn, but like most things, the more it is done, the easier it becomes. And with it, you will have the information at your fingertips to confirm that your model is built of components that are set up correctly, because you can simply review the keycards to confirm they were created in a way that corresponds to the design intent of that component.

Ready to explore the possibilities of LS-DYNA for your business? Contact the Rand SIM experts today. We can help through sales, training, and support or through a consulting engagement where we get everything up and running and make sure your team can take the reins by the end of the project.

About the Author

Conrad Magalis

Conrad Magalis is responsible for the adoption of advanced digital engineering practices at Rand Simulation. Conrad has a broad range of experience within manufacturing and industrial industries. His acumen is focused on progressive business and engineering decisions, with practical outcomes.

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