Sweep

Select the check box (active by default) to make the sweep operation create cross-sectional faces between the sweep sections. Such cross-sectional faces can be useful, for example, for a swept mesh where you want to specify the mesh distribution for each section of the sweep.

Select the edges you want to sweep along in the window. More than one edge can be selected, but the selected edges must form a nonclosed connected chain. The edges appear in the list. Click the button to toggle between turning ON and OFF the selections.

Select the check box to sweep in the negative edge direction.

The check box is selected by default. Clearing this check box means that transition zones are not added, which can give a better result in cases where the original edges already connect with a continuous tangent.

From the list, select one of the following options:

•

to use a similar parameterization but with a normalized arc length (values 0–1). If it is more suitable to express the scale factor and the twist angle using the original parameter, you can use the normalized arc length parameterization instead of the default arc length parameterization.

•

to use the parameterization that is stored in the geometry’s data structures. This is the parameterization used in earlier versions of COMSOL Multiphysics. It can also be useful if the edge that you sweep along do not need a parameterization, or a parameterization is unsuitable for that edge.

Select the check box to use the selected geometry objects for further geometry operations.

Select the check box to force the objects in the and lists to be included in the Form Union/Assembly operation. If the check box is not selected, these objects are not included in the Form Union/Assembly operation if the list or list contains all faces or edges in the objects.

This section contains a number of properties that determine how the face is transformed when swept along the spine curve.

A curve parameter name can be defined in the field. Use this parameter in the expressions defining scale factor and twist angle. The parameter is increasing along the chain of edges to follow. It is not the same as the parameter s1 available in Results. For a single edge created by a Parametric Curve, the parameter is the same as the parameter used in the Parametric Curve.

The field controls the size of the cross section face when swept along the spine curve.

The field controls the rotation angle of the cross section face about the spine curve.

By default, twist compensation is active and prevents the twisting that would otherwise occur due to nonzero torsion for nonplanar curves. Clear the check box to turn off this compensation. When is active, it behaves as if a term was added to the with a magnitude matching the integral of the torsion of the curve. This makes the edges in the sweep direction locally parallel to the spine curve. For a noncircular cross section, twist compensation also affects the shape of the generated object.

From the list, select an option to align the cross section to the spine curve:

•

Select (the default) to sweep the face starting from its original position. Using this setting, it is possible to create sweeps where the face is not perpendicular to the spine curve, and where the face does not contain that starting point of the spine curve.

•

Select to adjust the spine curve so that it starts on the face to sweep and so that it is parallel to the face normal at the point where it touches the face. The first part of the spine curve is replaced by a cubic Bézier curve, with the length of the replaced part, measured in parameter values, controlled by the value in the field.

•

Select to move the face to the start of the spine curve and orient the face perpendicularly to the spine curve. This setting is only allowed when the face is located in a work plane, and the movement is such that the work plane origin coincides with the spine curve.

From the list, select (the default) to represent the swept object using splines, or , to represent the swept object using Bézier curves. The difference is that using Bézier curves, the intersections between the surfaces that form the swept object are visible edges, whereas they are hidden when using splines.

The value in the field is a relative tolerance that controls the accuracy of the geometric representation of the swept object. The geometric representation is an approximation, which is necessary because it is not possible to exactly represent a swept object using NURBS (nonuniform rational basis splines). The default value is 10−4 (0.01%).

Internally, the software represents the swept object by B-spline curves and surfaces, which are computed to approximate the mathematical definition of the swept surface. The number of knot points in the splines increases automatically until the approximation satisfies the tolerance specified in the field or until it reaches the number of knots specified in the field (default value: 1000).

If more than one edge is selected in the list, the controls which edge is used to define the positive sweep direction. The is automatically set when the first edge is added to the list, so usually it does not have to be changed manually.

Select the check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the resulting objects consist of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option from the ( if in a geometry part) list: , , , , or . The default is , which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose . These selections do not appear as separate selection nodes in the model tree. Select to not make any selection available outside of the geometry sequence. From the list, choose a color for highlighting the resulting objects selection. See Selection Colors.