Chapter 17: Boundary Conditions

Boundary conditions refers to the available loads and constraints that can be applied to an analysis environment. This term is often used interchangeably with loads or supports. To accurately simulate the physical phenomena of an analysis environment, you need to apply boundary conditions.

Boundary conditions are typically applied to 2D and 3D simulations (with some exceptions). The type of analysis determines which boundary conditions you can use. Force, pressure, and heat flux are examples of loads you can apply to a geometry. Constant temperatures, supports that restrict motion, and displacements that specify motion are examples of constraints. You can define boundary conditions that act remotely and also import boundary conditions.

Boundary Conditions and the Environment Context Tab

Mechanical organizes boundary conditions on the Environment Context tab in the following categories:

  • Inertial

  • Loads

  • Supports

  • Conditions

  • Direct FE (mesh-based boundary conditions)

Applying a Boundary Condition

To apply a boundary condition, do the following:

  1. Select the desired boundary condition. The available boundary conditions depend on the type of analysis you are performing.

  2. Scope the boundary condition to a geometry or finite element selection. This identifies where the boundary condition acts.

    Tip:  You can first select geometric or mesh entities, then select a boundary condition.

  3. Specify the magnitude of the boundary condition.

  4. Specify whether the boundary condition magnitude is stepped or ramped (if applicable).

  5. Specify any additional properties needed to define the boundary condition, such as coordinate system and/or direction.

How to Use Boundary Conditions

The following topics describe how to use boundary conditions in your analysis.