When you are modifying a sketch, you can implement your changes by modifying a dimension, by moving selected vertices, or by trimming, extending, breaking, or merging edges. ABAQUS/CAE provides the following methods for trimming, extending, breaking, and merging edges:
Trim/Extend
You can trim or extend one end of a line or arc; you can also trim a spline curve, but spline curves cannot be extended. To trim or extend an edge, first select the edge near the end that you want to modify and then select a second edge to define an intersection point. The second edge may be any object in the sketch, including construction geometry. The intersection point may lie beyond the current endpoints of either selected edge. ABAQUS/CAE trims or extends the first edge at the intersection point and, if the intersection point lies on the second edge, breaks the second edge at the intersection point. If the intersection point is not on the second edge, you can repeat the process, reversing the selection order, to extend the second edge to the intersection point.
For detailed instructions on trimming and extending edges, see “Modifying Sketcher objects by trimming or extending edges,” Section 19.14.3.
Auto-trim
You can trim an intermediate or end segment from a line, arc, circle, or spline curve. Auto-trim is the fastest method you can use to remove unwanted edge segments from a sketch. ABAQUS/CAE uses preselection to highlight edges that you can remove. Preselection is based on cursor proximity and the two nearest “trim points.” Trim points include intersection points, endpoints, vertices, and the picked points that define the edges of circles. Unlike when you use Trim/Extend, ABAQUS/CAE does not break the intersecting edges. Figure 19–19 shows several possible trim combinations based on the circle and line shown in the upper left corner.
For detailed instructions on automatically trimming edges, see “Modifying Sketcher objects by automatically trimming edges,” Section 19.14.4.
Break
You can break edges, creating separate pieces with a common vertex, where they intersect in the sketch. Select the first edge to be broken, then select a second edge that intersects the first at the desired break point. As you move the cursor near the second edge, a circle appears around the break point that you would create. If there is more than one intersection point between the two edges, ABAQUS/CAE highlights the intersection closest to the cursor. If the second edge extends beyond the break point and is not construction geometry, ABAQUS/CAE breaks both edges at the indicated point. If multiple edges intersect at the break point, only the two edges that you selected will be broken. Figure 19–20 shows an intersecting line and spline on the left, indicates the break point in the center image (the cursor is not shown), and shows the four resulting edges on the right.
Note: Spline curves retain their exact shape when you break or trim them, but the control points are removed so you can no longer edit the shape of the curves.
For detailed instructions on breaking edges, see “Modifying Sketcher objects by breaking edges,” Section 19.14.5.
Merge
The Merge tool enables you to close small gaps in a sketch. These gaps commonly occur in the following situations:
When you use the Project Edges tool on edges that are not in a plane parallel to the sketch plane, the endpoints may be created in a slightly different location from other selected edges.
When you import sketch geometry into an existing sketch, the edges may not line up exactly.
The Merge tool is intended only for closing small gaps. Merging edges to close larger gaps may change the sketch geometry significantly. If you want to move elements in a sketch over a large distance, use the vertex modification tool from the Sketcher toolbox to translate vertices in your sketch to a new location. For more information, see “Moving and resizing Sketcher objects by moving their vertices,” Section 19.14.1.
For detailed instructions on merging edges, see “Modifying Sketcher objects by merging edges,” Section 19.14.6.
