The part seeding tool allows you to specify a target element size when you are seeding a part or a part instance. If the geometry of the part 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 vary in size, the resulting mesh may be too coarse to adequately represent any small features, as shown in Figure 17–8.
To avoid the problem of inadequate seeding around small curved features, ABAQUS/CAE applies curvature control when it seeds a part or part instance. Curvature control allows ABAQUS/CAE to calculate the seed distribution based on the curvature of the edge along with the target element size. Figure 17–9 shows the same part seeded and meshed with curvature control enabled.
The Global Seeds dialog box allows you to specify how curvature control will influence the seeding. You can configure the following:
Deviation factor
The deviation factor is a measure of how much the element edges deviate from the original geometry, as shown in Figure 17–10.
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
Specifying a minimum size 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.
