# Knuckle Calculation Examples - Intergraph Smart 3D - Reference Data

## Intergraph Smart 3D Structural Manufacturing Reference Data

PPMProduct
Intergraph Smart 3D
PPMCategory_custom
Reference Data
Version_S3D
12.x(2018)

The delivered butt weld parameter rules handle both planar plates and knuckled plates. The geometry and calculations used are shown in the following set of examples.

Butt Weld 1 Knuckle Calculation

Butt weld parameter rule1 checks for the presence of a knuckle. If a knuckle exists, it bisects the CornerButtMountingAngle, and adds that amount to 90 degrees to get the Nose Orientation angle. Note that if the CornerButtMountingAngle is returned as the bigger of the two possibilities, the amount is subtracted from 180 before the angle calculation.

Butt Weld 2 Knuckle Calculation

Butt weld 2 uses the same calculation for the nose orientation angle as butt weld 1. It then uses the mounting angle to calculate the bevel angle. The bevel angle (BA) is still measured off of the plate normal, so it is the additional small angle that should be cut to match the required opening angle of the bevel.

Butt Weld 3 Knuckle Calculation

Butt weld 3 is similar to butt weld 2, with an additional bevel on the inside face of the knuckle. The inside bevel angle (BA2) is also measured from the plate normal, so the angle that is calculated needs to be bigger, to match the required opening angle.

Butt Weld 4 Knuckle Calculation

Butt weld 4 handles the case of an unsymmetrical knuckle. Therefore, one of the two plate edges remains square or unbeveled, while the other is beveled to provide the required opening angle. You can flip the beveled part.