seam-quad (angled)

Restriction: Available in Abaqus, Nastran and OptiStruct.

Creates one quad row under a certain angle. The angle is measured between the quad row and the perpendicular projection from the free edge to the opposite shell link. In addition, a certain pure quad element pattern is created around the seam elements, shown here in red. These elements normally get imprinted into the shell links. The exact geometry of the seam can be influenced by the angle value.

This realization is can be used for both, lap- and T-welds.
Note: You can revert the direction of quad seam connectors during the next realization by activating the reverse direction checkbox in the Seam panel.


Figure 1.

Quad Realization Options

Exclusive options available for seam realization types with a quad row representing the connection. Not all of these settings have to be defined for all quad realization types.


Figure 2.
Option Action
weld angle Define the distance between the normal projection and the quad direction.

Principally it is allowed to define weld angles between 0.0 and 90.0. If the value is set to 0.0 an internal thickness-based calculation is used. If the value is set to 0.0 and no thickness is defined the connector will fail.

If the angle is created in the wrong direction, the seam can be reverted by enabling the reverse direction checkbox and performing a rerealization.
cap angle Depending on the seam-quad type, the cap angle is measured differently.
  • Measured between the normals of the cap element and the second-to-last element of the seam.
  • Measured between the edge normals of the cap element and the second-to-last element of the seam in the plane of the opposite link.

Cap angles are created by default. Clear this checkbox to remove cap angles and runoff angles.

Cap angles between 0.0 and 45.0 are permitted, but be aware that larger values can lead to bad elements. The recommended value is 10.0 or smaller. Cap angles between 45.0 and 90.0 are permitted, but be aware that smaller values lead to bad elements. The recommended value is 75.0 and higher.
Note: Only available for seam-quad (angled + capped + L) and seam-quad (angled + capped + T).
runoff angle Depending on the seam-quad type, the runoff angle is measured differently.
  • Measured between the normals of the last and the second-to-last last element of the seam.
  • Measured between the edge normals of the last and the second-to-last element of the seam in the plane of the opposite link.
Clearing the cap angles checkbox removes runoff angles, which are created by default.
height Define the distance between the projection point and the start-point of the angled quads.
Note: Only available for T-seams.
The height needs to be chosen in an extent to bridge the gap between the links. Also, the height strongly influences the quad length, especially in cases of very large weld angles.