The First Design

This method assumes origin at the centroid, with the web along the y axis and the length of the beam along the z axis. Four stages of construction for this design are shown in Figure 4.12. These pictures show the model after the first, second, fifth, and final steps.

Construction:

1. Insert Rectangle Height Web_Ht Width Web_Th Ctr Loc [0,0,0]
2. Insert Line Free Ref Loc [0,0,0] Dxy Flange_2 Web_Ht_2 Dy -Fl_Th Xangle -Draft Dx Flange_2 Xangle Draft Dx Flange_2 Dy Flange_Th Dx -Flange
3. Join Pcurve Chn (select previous Line)
4. Duplicate Entity (select previous Pcurve) Mirror Plane Y Loc [0,0,0]
5. Union Profile (select all curves)
6. Break Pcurve (select new profile)
7. Insert Fillet Radius Fillet (select each of four corners to be filleted)
8. Insert Fillet Radius Round (select each of four corners to be filleted)
9. Join Pcurve Chn (select curve)

Figure 4.12: Steps in Creation of the Beam, First Design

Variables:

Variable - description                  Type    Value From
Draft - draft angle on inside of beam   const   table
Fillet - radius of corner fillets       free    table/eqn
Flange - width of flange                const   table
Flange_2 - half of width of flange      free    eqn
Fl_Th - thickness of flange             const   table
Min_Radius - minimum allowable radius   const   constant
Round - radius of inside rounds         free    table/eqn
Web_Ht - height of web                  const   table
Web_Ht_2 - half of height of web        free    eqn
Web_Th - thickness of web               const   table

Equations:

Flange_2 = Flange / 2
Web_Ht_2 = Web_Ht / 2
Fillet >= Min_Radius
Round >= Min_Radius

The Min_Radius variable was added because CADDS5 is incapable of inserting a fillet or round with a zero radius. From experimentation, the smallest possible value is 0.0025.

Last Modified: Wed Aug 28 14:41:29 EDT 1996