Understanding when to Take Advantage of Symmetry - Lesson 3

In this lesson, we will show when to take advantage of symmetry. If the geometry, material orientation, loading, and expected response all exhibit symmetry about the same planes, we can take advantage of planar symmetry and only model a portion of the actual structure to reduce analysis run time and memory requirements. Using Symmetry Regions in Ansys Mechanical can give more accurate and more computationally efficient solutions. However, the Symmetry Region tool should not be used when all four symmetry requirements are not satisfied, such as in modal or linear buckling analyses where non-symmetric modes are needed to be calculated. We will give a short lecture, then get into Mechanical to illustrate the concepts on a mechanical part.

Alternate video link.

Video Highlights

2:11 - General rule for a planar symmetry boundary condition

2:46 - Defining the Symmetry Region for planar symmetry

4:46 - Visual expansion of symmetry results to show “full” model for planar case

5:28 - Understanding the conditions when Symmetry Region shouldn’t be used

8:55 - How to Split bodies for symmetry in Ansys Discovery?

11:20 - How to connect line bodies with solid bodies via Contact Region in Ansys Mechanical?

12:20 - How to create and align local Coordinate Systems based on geometry?

13:21 - How to create Symmetry Region in Ansys Mechanical?

14:14 - How to define Bolt Pretension load in Ansys Mechanical?

16:20 - How to visually expand symmetry model results to show “full” model for a sector?

Simulation Files

Download the accompanying geometry and archived files here. Ansys Student can be downloaded for free here.