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Manufacturing Solutions

Normals Panel

User Profiles:

Incremental_LS-DYNA

Die Module

Use the Normals panel to display and reverse the normals of elements or surfaces. The orientation of element normals can also be adjusted. The normal of an element is determined by following the order of nodes of the element using the right-hand rule.

For the Abaqus interface this panel can be used to adjust or reverse the stacking direction of continuum shells.

Panel Usage

The Normals panel consists of two subpanels for adjusting element and surface normals.

Normals can be reviewed showing a vector or by colors. A vector shows in positive normal direction, while the color mode shows the positive side of a shell or surface in red and the negative side in blue.

 Normals using vectors (for explanation purposes some elements have been set to transparent mode) Normals using colors (red = positive and  blue = negative)

Subpanels and Inputs

The Normals panel contains the following subpanels:

 Elements

Use the Elements subpanel to display and reverse the normals of elements. Select elements indirectly by components or directly by elements, or elect to have all of the displayed 2D elements selected automatically. Click display to review the current normal orientation of the selected elements. Optionally, click reverse to flip the normals to the opposite side (reverse the normals).

You can also use the Elements subpanel to adjust element normals. Select elements to adjust, then select an orientation method which determines how element normals are adjusted. When you are finished, click adjust. Optionally, select display adjusted only to only display the elements which have been adjusted in this operation. All elements selected for adjusting must be in a continuous mesh for this operation.

On review, normals are displayed with vectors by default. Alternatively, you can choose to display normals in color mode by switching the toggle from vector display normals to color display normals. Normals pointing in the wrong direction can be spotted easier in bigger meshes when using the color display mode. Red indicates the positive normal direction and blue indicates the opposite side of the element.

In vector mode, specify the size of normals in the size field. If this value is zero, the normal is sized based on the smallest side of the element. If a value other than zero is specified for size, the normal is drawn based on the length specified in model units.

The elements subpanel is also made available in the composites panel on the 2D page.

displayed 2D elems/comps/elems

Use the switch to select elements to display, adjust, or reverse the normals of.

 • displayed 2D elems (default) automatically selects displayed 2D elements
 • comps enables you to indirectly select elements via components
 • elems enables you to directly select elements

When you select elems, click the switch to change the selection mode.

elems

Select individual elements, or select all of the elements contained by a component or on a surface.

2D faces

Select all of the elements on a 2D face.

If there are discontinuities on a face, then only the elements inbetween the discontinuities will be selected.

2D faces ext

Select all of the elements on a 2D face that contain discontinuities.

orientation

Determines how element normals are adjusted.

 • auto adjusts the normals for all elements to be consistent with the dominant normal direction that exists within each connected section.
 • elem adjusts the normals for all elements to be consistent with the reference element you select.
 • surfaces adjusts the normals for selected elements that are associated with surfaces to match the normal of their surface.
 • vectors adjusts the normals for selected elements to best align with the specified vector direction.

use feature angle

When enabled, you can enter a feature angle (mode=4, and a feature_angle is used). For each connected section, the normals are adjusted for all elements in that section to be consistent with the 'dominant normal direction' already existing within that section, with the sections defined based on the specified feature angle.

When disabled, the mode=0, and no feature_angle is used.

vector display normals / color display normals

Choose a method to review normals of elements. Normals can be shown as vectors or by color code. In color mode, red indicates the positive normal direction, while blue indicates the negative direction.

size =

Adjusts the vector size if vector display normals is selected. If a value greater than zero is specified it shows the normal in that size based on model units. Otherwise, the vector size is equivalent to the smallest size of the element.

Displays the normals which have been changed when you click adjust.

display

Displays the normals of selected elements or surfaces as vectors or in color mode (see above).

Adjusts normals based on the orientation method you specified.

reverse

Flips all the normals of selected elements or surfaces.

Face angle

The face angle is the angle between the normal of facets that share an element edge. A facet can either be a shell element itself, or one of the faces of a solid element. The normal of triangular facets is that of the plane defined three corner vertices. Whereas, the normal of quadrilateral facets is calculated by taking the cross-product between its two diagonals. This special treatment for quadrilaterals is because a warped shape does not lie completely on a plane.

Only available when the entity selector is set to elems and the selection mode is set to faces or 2d faces ext.

Individual Selection

Select individual elements on a face or select individual free/shared edges of elements.

Only available when the entity selector is set to elems and the selection mode is set to faces.

 Surfs

Use the Surfs subpanel to display and reverse normals of surfaces. Select surfaces indirectly by components or solids or directly by surfaces, or elect to have all of the displayed surfaces selected automatically. Click display to review the current normal orientation of the selected surfaces. Optionally, click reverse to flip the normals to the opposite side (reverse the normals). After clicking display or reverse, the normals will either be shown as vectors or in color mode, depending on the setting of the vector display normals/color display normals toggle.

Adjust the vector size by entering a value in the size field. The vector will either be drawn in model units based on the value or the vector size will be 10% of the screen if zero is entered.

The minimum set of surfaces required is automatically adjusted to maintain overall consistency of the surface normals, without affecting other surfaces, based on the input surface selection. The minimum set of surfaces is found from all surfaces attached by shared edges. This includes the entire surface shell, not just the adjacent surfaces. This prevents problems that can arise from incorrect or inconsistent orientations.

This task can be performed in three panels: Normals, Surface Edit (offset subpanel), and Midsurface (create subpanel, solid option). In each of these panels, you can first view the surface normals by clicking show normals. You can also choose between vector display and color display of normals.

displayed surfs/comps/surfs/solids

Use the switch to select surfaces to display or reverse the normals of.

 • displayed surfs (default) automatically selects displayed surfaces
 • surfs enables you to directly select surfaces
 • comps enables you to indirectly select surfaces via components
 • solids enables you to indirectly select surfaces via solids

Adjusts the FE orientation of normals associated with the selected surfaces when reverse is clicked.

vector display normals / color display normals

Choose a method to review normals of surfaces. Normals can be shown as vectors or by color code. In color mode, red indicates the positive normal direction, while blue indicates the negative direction.

size =

Adjusts the vector size if vector display normals is selected. If a value greater than zero is specified it displays the normal in that size based on model units. Otherwise, the vector size is equivalent to 10% of the screen.

reverse normals

Flips all the normals of selected surfaces.

Additional functionality in the normals panel is available for the Abaqus interface if entered through the Composites panel of the 2D page. This helps to set up models using continuum shell elements. It applies to elements with the HyperMesh configurations penta6, penta 15, hex8 and hexa20.

When display is clicked, the default stack direction is displayed without considering the property assigned to the underlying elements. The review is based on the numbering scheme of the continuum shell element. The display stack direction button shows the stack direction of all selected elements considering the setting of the elemental property. Supported are all three isoparametric directions as well as the definition by a system (*ORIENTATION). Normals are either displayed as vectors, or colors when in the color display normals mode (the bottom face shows in blue, and the top face in red).

You have two options to use adjust normal:

 • by reference element: The default stacking direction of all selected elements can be adjusted to a reference element which needs to be selected with the elem selector. This algorithm only works on models with one layer of continuum shell elements.
 • by nodes on bottom face: Selected elements will be adjusted by selecting the nodes on the bottom face of one element. The stack direction will then point from the bottom face to the opposite face of the element. For hexahedron elements, two diagonal nodes or three nodes can be selected; for pentahedron elements three nodes need to be selected. This algorithm also works for multiple layers of elements.

Adjust normal by nodes on bottom face: Either two nodes a and b, or an additional
node c can be selected to define the bottom face for a continuum shell element.

Reverse normal and reverse stack direction return the stacking direction to the opposite.

Adjust normal and both reverse functions affect the element numbering. Applied loads are automatically corrected upon adjustment to apply to the correct face of the element.