Applying curvature control to your seeding

The part seeding tool allows you to specify a target element size when you are seeding a part, a part instance, or multiple edges. If the geometry is relatively regular, specifying a single target element size can result in an acceptable mesh. However, if you specify a single target element size and the geometric features that make up the part or edges vary in size, the resulting mesh may be too coarse to adequately represent any small features, as shown in Figure 1.

Figure 1. Seeding and the resulting mesh with no curvature control.

To avoid the problem of inadequate seeding around small curved features, Abaqus/CAE applies curvature control when it seeds a part, a part instance, or edges. Curvature control allows Abaqus/CAE to calculate the seed distribution based on the curvature of the edge along with the target element size. Figure 2 shows the same part seeded and meshed with curvature control enabled.

Figure 2. Seeding and the resulting mesh with curvature control enabled.

You can configure the following to specify how curvature control will influence the seeding:

Deviation factor

The deviation factor is a measure of how much the element edges deviate from the original geometry, as shown in Figure 3.

Figure 3. Deviation factor.

To help you visualize the deviation factor, Abaqus/CAE displays the approximate number of elements it would create around a circle corresponding to the setting that you enter. As you reduce the deviation factor, the number of elements that Abaqus/CAE would create around a circle increases. This number is only a visual aid; for example, if you are seeding a spline or an ellipse, Abaqus/CAE creates a different number of elements, depending on the local curvature along the edge.

Specify minimum size factor

Specifying a minimum size factor prevents Abaqus/CAE from creating very fine meshes in areas of high curvature that you have no interest in modeling; for example, kinks in spline curves or fillets with a very small radius. The number that you enter representing the minimum size is the fraction of the global seed size. As a result, if you change the global seed size, you do not have to change the minimum size factor.

For detailed instructions on applying curvature control, see Defining seed density for an entire part or part instance.