Member Descriptions [name, end point names, weight (if in objective function), second power of length (if a constraint), member category, Obj/Con/Exc (put in objective function, use as a constraint or exclude from computations), flags] For assembly purposes, only the name and end point names are of interest. The other information may be of interest after A Practical Guide to Tensegrity Design has been consulted. <Member> 01(c) pt01 pt02 0.0 sqr(1.0) 2 Con * <Member> 02(c) pt02 pt03 0.0 sqr(1.0) 2 Con * <Member> 03(c) pt03 pt04 0.0 sqr(1.0) 2 Con * <Member> 04(c) pt04 pt05 0.0 sqr(1.0) 2 Con * <Member> 05(c) pt05 pt06 0.0 sqr(1.0) 2 Con * <Member> 06(c) pt06 pt07 0.0 sqr(1.0) 2 Con * <Member> 07(c) pt07 pt08 0.0 sqr(1.0) 2 Con * <Member> 08(c) pt08 pt01 0.0 sqr(1.0) 2 Con * <Member> 09(c) pt01 pt09 1.0 sqr(2.1) 7 Con * <Member> 10(c) pt02 pt10 1.0 0.0 3 Obj * <Member> 11(c) pt03 pt11 1.0 0.0 3 Obj * <Member> 12(c) pt04 pt12 1.0 0.0 3 Obj * <Member> 13(c) pt05 pt13 1.0 0.0 3 Obj * <Member> 14(c) pt06 pt14 1.0 0.0 3 Obj * <Member> 15(c) pt07 pt15 1.0 0.0 3 Obj * <Member> 16(c) pt08 pt16 1.0 0.0 3 Obj * <Member> 17(s) pt01 pt16 -1.0 0.0 1 Obj * <Member> 18(s) pt02 pt09 -1.0 sqr(3.0) 1 Con * <Member> 19(s) pt03 pt10 -1.0 0.0 1 Obj * <Member> 20(s) pt04 pt11 -1.0 0.0 1 Obj * <Member> 21(s) pt05 pt12 -1.0 0.0 1 Obj * <Member> 22(s) pt06 pt13 -1.0 0.0 1 Obj * <Member> 23(s) pt07 pt14 -1.0 0.0 1 Obj * <Member> 24(s) pt08 pt15 -1.0 0.0 1 Obj * <Member> 25(c) pt09 pt10 0.0 sqr(0.8) 2 Con * <Member> 26(c) pt10 pt11 0.0 sqr(0.8) 2 Con * <Member> 27(c) pt11 pt12 0.0 sqr(1.0) 2 Con * <Member> 28(c) pt12 pt13 0.0 sqr(1.0) 2 Con * <Member> 29(c) pt13 pt14 0.0 sqr(0.8) 2 Con * <Member> 30(c) pt14 pt15 0.0 sqr(0.8) 2 Con * <Member> 31(c) pt15 pt16 0.0 sqr(1.0) 2 Con * <Member> 32(c) pt16 pt09 0.0 sqr(1.0) 2 Con *
In-Situ Member Lengths These are the lengths of the members when they are in place and prestress is applied. The strut lengths are from pin insertion point to pin insertion point, as are the tendon lengths. The values are in model units. 01(c): 1 02(c): 1 03(c): 1 04(c): 1 05(c): 1 06(c): 1 07(c): 1 08(c): 1 09(c): 2.1 10(c): 2.79295 11(c): 3.12529 12(c): 2.93865 13(c): 2.2802 14(c): 1.47522 15(c): 0.981849 16(c): 1.30782 17(s): 2.10244 18(s): 3 19(s): 3.64012 20(s): 3.81178 21(s): 3.20853 22(s): 2.12729 23(s): 1.32768 24(s): 1.32601 25(c): 0.8 26(c): 0.8 27(c): 1 28(c): 1 29(c): 0.8 30(c): 0.8 31(c): 1 32(c): 1
Relative Member Force Magnitudes These values are useful for developing an assembly strategy for the structure. The tighter tendons are much easier to tie in place early on, while the looser tendons can be left to the last. This information is also used to adjust tendon lengths since the measured length of a tendon will be shorter for a highly-stressed tendon with the same in-situ length as a tendon which is not so stressed. 01(c): 1.18407 02(c): 1.25909 03(c): 1.18407 04(c): 1.09222 05(c): 1.18407 06(c): 1.25909 07(c): 1.18407 08(c): 1.09222 09(c): 2.1 10(c): 2.79295 11(c): 3.12529 12(c): 2.93865 13(c): 2.2802 14(c): 1.47522 15(c): 0.981849 16(c): 1.30782 17(s): -2.10244 18(s): -3 19(s): -3.64012 20(s): -3.81178 21(s): -3.20853 22(s): -2.12729 23(s): -1.32768 24(s): -1.32601 25(c): 1.22347 26(c): 1.22347 27(c): 1.38094 28(c): 1.38094 29(c): 1.22347 30(c): 1.22347 31(c): 1.38094 32(c): 1.38094
Construction Lengths (in millimeters and halves) The construction length of a tendon is less than the in-situ length since when the tendon is measured off it isn't under any prestress force. The construction length for the strut represents the length of the 3/16-inch-diameter wooden dowel. The tendons were made of 12-lb.-test braided nylon fishing line. In this case, the attachment point at the hubs was a simple metal pin stuck into the end of the strut, so no member-length adjustments were necessary. Prestress forces are assumed not to affect strut lengths. Elongation of Tendon of Unit Cross Section Under Force of Average Magnitude (fraction)> .02 Length Scale Factor> 60 Strut and Tendon Hub Adjustments - s;t> 0 0 01(c): 59 0 02(c): 59 0 03(c): 59 0 04(c): 59 0 05(c): 59 0 06(c): 59 0 07(c): 59 0 08(c): 59 0 09(c): 122 1 10(c): 161 1 11(c): 180 0 12(c): 170 0 13(c): 133 0 14(c): 87 0 15(c): 58 0 16(c): 77 0 17(s): 126 0 18(s): 180 0 19(s): 218 1 20(s): 228 1 21(s): 192 1 22(s): 127 1 23(s): 79 1 24(s): 79 1 25(c): 47 0 26(c): 47 0 27(c): 59 0 28(c): 59 0 29(c): 47 0 30(c): 47 0 31(c): 59 0 32(c): 59 0
Skew Eight-Prism with Point Labels
structure file: sk8prsm/stage1.rc variable file: sk8prsm/stage2.dat digit list: src/mm.dls |
CONTACT: Bob Burkhardt Tensegrity Solutions Box 426164 Cambridge, MA 02142-0021 USA e-mail: bobwb@juno.com |