The Roller node adds a roller constraint as the boundary condition; that is, the displacement is zero in the direction perpendicular (normal) to the boundary, but the boundary is free to move in the tangential direction. A
Roller condition is similar to a
Symmetry condition, but the latter has some other options.
For Automatic, the constraint is applied in the direction normal to the boundary, as represented by the mesh. This orientation is not updated during the analysis.
For Plane, select
Orientation of normal —
X-axis,
Y-axis,
Z-axis, or
User defined to describe the constraint direction. When
User defined is used, enter the vector
en, pointing along the normal to the plane along which the boundary is sliding.
For Cylinder, select
Axis type—
X-axis,
Y-axis,
Z-axis, or
User defined to describe the orientation of the cylinder. Enter the location of a
Point on axis,
Xc, in order fix the location of the cylinder. When
User defined is used, enter the vector
es, pointing along the axis of the cylinder. The constraints will act radially from the cylinder axis. If the analysis is geometrically nonlinear, each mesh node is assumed to maintain its distance from the cylinder axis.
For Sphere, enter the location of the
Center of sphere,
Xc. The constraints will act radially from this point. If the analysis is geometrically nonlinear, each mesh node is assumed to maintain its distance from the center of the sphere.
) and select Advanced Physics Options in the Show More Options dialog box. 
