Setting up an Inertia Relief Analysis
To perform an inertial relief analysis, you add an Inertia Relief node to the physics interface. You should not use any other types of constraints or elastic supports. The structure must be able to move freely as rigid body. The constraints needed to avoid singularity are added internally.
If you have several structural mechanics interfaces in your model, you should add an Inertia Relief node to each of them.
You can use any type of external loads, such as point loads, boundary loads, or forces on rigid objects.
In most cases, you do not need to change any settings in the Inertia Relief node. The constrained points will be automatically chosen by the program. You can, however, control which points that are used for the constraints. To do that, change Control points to From selection input. Some examples of cases when you may need to select the control points manually are:
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A point load is applied to a point.
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There are internal constraints (for example from multiphysics couplings) at a point.
When From selection input is selected, a Point Selection section is shown. Select the points to be used for constraining the domain.
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In 3D, select three points that are not collinear.
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In 2D, select two points.
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In 2D axisymmetry, select one point, not on the axis of rotation.
The next step is to prepare the model for the analysis. Click the Create Load Groups and Study button. If you have more than one physics interface, you should only click the Create Load Groups and Study button in one of them.
Do not manually edit the created load groups, or the settings for the load case handling in the study.
A special set of load groups will be added, together with a new study. This study consists of two stationary study steps. In the first step, a number of load cases (six in 3D) are solved. Using these load cases, a rigid body acceleration is determined, using the conditions that the external loads are balanced by inertia forces. In the second study step, the external load and the computed inertia forces are all combined together to form the total solution.
Once you have run the special training study for inertia relief, any other study will contain the computed rigid body acceleration field. If the external loads are changed, then you need to re-run the training study.
Bracket — Inertia Relief Analysis: Application Library path Structural_Mechanics_Module/Tutorials/bracket_inertia_relief