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## What is rigid body in Abaqus?

In ABAQUS a rigid body is a collection of nodes and elements whose motion is governed by the motion of a single node, known as the rigid body reference node, as shown in Figure 3–7. The shape of the rigid body does not change during a simulation but can undergo large rigid body motions.

How do you create a rigid body constraint in Abaqus?

Defining rigid body constraints

1. From the main menu bar, select ConstraintCreate.
2. In the Create Constraint dialog box that appears, do the following:
3. From the editor, select all of the regions that you want to include in the rigid body.

### What is analytical rigid in Abaqus?

Analytical rigid. An analytical rigid part is similar to a discrete rigid part in that it is used to represent a rigid surface in a contact analysis. However, the shape of an analytical rigid part is not arbitrary and must be formed from a set of sketched lines, arcs, and parabolas.

What is rigid body in FEA?

Finite elements are deformable, whereas rigid bodies move through space without changing shape. The advantage of rigid bodies over deformable bodies is that the motion of a rigid body is described completely by no more than six degrees of freedom at a reference node.

## What is rigid body model?

A rigid body mode is defined as the free translation or rotation of a body without undergoing any significant internal deformation. This means the body will not undergo any internal deformation but will be able to move or rotate freely. These first 6 modes will have zero or close to zero modal frequency.

How do you assign a reference point to a rigid body Abaqus?

Assigning the rigid body reference point

1. From the main menu bar, select ToolsReference Point.
2. Select one of the vertices on the circumference of the pin. Abaqus/CAE labels the vertex RP to indicate that the reference point has been assigned to it.

### How do I create a constraint in Abaqus?

To create constraints:

1. From the main menu bar, select Constraint Create.
2. In the Create Constraint dialog box that appears, do the following:
3. Click Continue to create the constraint and to close the Create Constraint dialog box.
4. If applicable, select the region to which to apply the constraint.

What is the difference between discrete rigid and analytical rigid in Abaqus?

On a very simple note: Analytical rigid surfaces are defined mathematically using lines and arcs, whereas Discrete rigid surfaces are meshed using rigid elements. Basically, if your rigid surface can be created by extruding or revolving lines and arcs then use analytical. If not, then you have to use discrete rigid.

## What are analytical surfaces?

Analytical rigid surfaces are geometric surfaces with profiles that can be described with straight and curved line segments. These profiles can be swept along a generator vector or rotated about an axis to form a three-dimensional surface.

What are rigid body modes?

A rigid body mode is defined as the free translation or rotation of a body without undergoing any significant internal deformation. This means the body will not undergo any internal deformation but will be able to move or rotate freely.

### How is a rigid body defined in an Abaqus model?

An ABAQUS model can be defined in terms of an assembly of part instances (see “Defining an assembly,” Section 2.9.1). A rigid body in such a model can be created from deformable elements at either the part level or the assembly level. In either case all node and element definitions must belong to one or more parts.

How does Abaqus account for mass and rotary inertia?

Abaqus will account for the mass and rotary inertia contributions from all elements on a rigid body; therefore, if you want to assign the rigid body mass properties directly, you should take care to ensure that contributions from other element types that are part of the rigid body do not affect the desired input mass properties.

## Can a analytical surface be part of a rigid body?

Analytical surfaces can also be made part of the rigid body, whereas any surfaces based on the nodes or elements of a rigid body are associated automatically with the rigid body. The motion of a rigid body can be prescribed by applying boundary conditions at the rigid body reference node.

How does the Assembly interface work in Abaqus?

The assembly interface in Abaqus allows analysts to create a finite element mesh using an organizational scheme that parallels the physical assembly. In Abaqus the components that are assembled together are called part instances. This section explains how to organize an Abaqus finite element model in terms of an assembly of part instances.