ANSYS Calculations: DC Distortions Sense Wires with Varying Tension Shortest wire (m)0.3 Longest wire (m)4 Difference between short and long wires3.7 Division Average wire location along end plate Average Length per Division % of full wire tension Wire sag (microns) Sense wire tension (g) Operating stress (Mpa) % of Yield Strength Stretch (mm)
Region 1 Distortions Summary Division (1 at nose, 7 at backplate) Total wire tension (lb) Total wire tension (N) Wire Sag (horizontal wire) (micron) End Plate Deflection due to wire load (micron) Wire end displacement (microns up from nose)
Region 2 Distortions Summary Division (1 at nose, 7 at backplate) Total wire tension (lb) Total wire tension (N) Wire Sag (micron) End Plate Deflection due to wire load (micron) Wire end displacement (microns up from nose)
Region 3 Distortions Summary Division (1 at nose, 7 at backplate) Total wire tension (lb) Total wire tension (N) Wire Sag (micron) End Plate Deflection due to wire load (with posts) (micron) Wire end displacement (microns up from nose)
“Pre-bow” or “build-flat” ? - how large are the corrections? “Pre-bow”“Build-flat” Endplate deflection Reg 1,2,3: 680, 620, 25 m Reg 1,2,3: ~ +/-250 m Maximum wire sag 1 Reg 1,2,3: 120, 310, 595 m Middle wire sag Reg 1,2,3: 80, 200, 400 m Middle wire total 2 Reg 1,2,3: 690, 650, 400 m Reg 1,2,3: 260, 320, 470 m 1.“wire sag” is for a horizontal wire; ~ half that for top/bottom sectors ~ zero for sectors 1 & 4 2.“wire total” is the quadratic sum of endplate deflection and wire sag
“Pre-bow” or “build-flat” ? “Pre-bow”“Build-flat” Pro smaller deflection smaller correction to wire position simpler, more accurate, construction simpler final shape Con harder to model shape must still do wire-sag correction less accurate layup (chamber to chamber) larger correction to wire position (in general, a larger correction gives a larger systematic error)
“Pre-bow” or “Build flat” ? “Build-flat” more accurate chamber to chamber “Build-flat” larger corrections but simpler to model from survey data simpler to correct in software In either case, we must do software corrections for chamber distortions