I'm not sure how to do it with the Sheet Metal workbench.
You can do it in the Part Design workbench by drawing two sketches of the start and ending cross-sections (the end will be 90 deg rotated from start), and then use the LOFT to make the twisted solid.
I'm not sure why you want 9 profiles (cross-sections)? 2 profiles should be enough to make the 90deg twist. Maybe you don't want constant twisting angles?
I am not obtaining the twist throught 90 deg with 2 profiles.have try all sort but no luck, it should be simple to twist a 20mm x 3mm through 90 deg.( i am new to catia it's part of a learning curve)
I just looked at the help file on Multi-Section solids, and it's not very good. :-(
I also tried one and it was pretty simple.
I drew two planes 60mm apart, and then drew the two sketches of the 20x2 cross sections (with one rotated 90deg). In the Part Design workbench, pick the LOFT icon for the multi-section solid. Then select both sketches (for section no 1 and 2), and hit OK.
I didn't like the results, cause it didn't have good transitioning at the ends, so I undid it and started again:
Pick the LOFT icon, select the first sketch and then select the plane of that sketch (it shows up in the tangent column), now pick the second sketch and the second plane. OK and you get a good twisted solid.
Another way to do this without using surfaces is to use the RIB feature. First draw one section. Then make a helix curve from one of the corner points, twisting 90deg. You should be able to now use RIB to sweep the section along the helix. (I didn't try this one, but you get the idea)
I tried several ways of doing this in GSD and got tbe best result using Loft with 2-Sections and 2-Guides. Without the guides, the transition surface necked in at the middle. Using sections of unit length, the dimension across the twist at the centre was the Cosine of Half the Twist Angle, irrespective of whether the twist was 90°, or any other angle.
Using 3-Sections only, I got a result but it was unacceptable, it's the guide curves that hold the smoothness of the twist. One guide was a Spline through 3-Points with Tangency on the start and finish points. The other guide was a symmetry operation performed on the first.
Another method is to use Sweep, with only 1-Section and 2-Guides.
The picture shows a Thick Surface made from the original twist plus linear ends, joined together.
After my last post, I realised that the twist can be even simpler and probably more accurate, with minimal construction work. The complete mid, or neutral, surface of the twist can be made from a line and a plane. The line is the linear length of the twist and the plane, in this case XY, is to reference the twist angle from.
Using Sweep and the With Reference Surface option, the line is the guide and the plane is the reference surface, the lengths are equally half the width of the twist and the angle is cotrolled by a S-type law. The straight ends are extruded from the implicit boundaries of the twist, using the original line for direction.
