19.8.6 Offsetting objects

You can offset objects in your sketch to create similar objects of a larger or smaller size. You select the edges to offset and the offset distance; ABAQUS/CAE displays a preview so that you can choose the offset direction. You can offset any continuous open or closed loops that do not contain branches. Figure 19–25 shows the two possible offsets that can be created for several edge selections. (For clarity, vertices and datum points are not shown in the figure.)

Figure 19–25 Offsets of a spline curve, a square, and a circle.

ABAQUS/CAE offsets each object in the same way that you would offset edges on paper with a drafting compass. Using a compass, you would draw the compass point along the original edge tracing a new edge with the pencil at the required perpendicular (offset) distance. At any sharp corners, you would rotate the compass to make it perpendicular to the second edge at the corner. At the end of this process, you would trim any offset edges that intersected with other offset edges. As shown in Figure 19–25, ABAQUS/CAE completes a similar process:

Straight edges are copied.
Offset edges that overlap, such as corners offset toward the “inside,” are trimmed to make new corners.
Where corners are offset toward the “outside,” you can choose to create sharp corners or fillets with radii equal to the offset distance.
Radii of existing curves are increased or decreased by the offset distance.

If the radius of a curve would be decreased to zero or less by the offset, ABAQUS/CAE creates a new vertex joining the surrounding edges that were previously connected by the curve. For detailed instructions, see “Offsetting the edges of Sketcher objects,” Section 19.18.3.