Finite elements and rigid bodies are the fundamental components of
an
Abaqus
model.
Finite elements are deformable, whereas rigid bodies move through
space without changing shape. While users of finite element analysis programs
tend to have some understanding of what finite elements are, the general
concept of rigid bodies within a finite element program may be somewhat new.
For computational efficiency
Abaqus
has a general rigid body capability. Any body or part of a body can be defined
as a rigid body; most element types can be used in a rigid body definition (the
exceptions are listed in
Rigid Body Definition).
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. In contrast, deformable elements have many degrees of freedom
and require expensive element calculations to determine the deformations. When
such deformations are negligible or not of interest, modeling a component as a
rigid body produces significant computational savings without affecting the
overall results.