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(0.261008730199888) 2 Con * <Member> 02(c) pt02 pt03 0.0 sqr(0.301915332950701) 2 Con * <Member> 03(c) pt03 pt04 0.0 sqr(0.383095246542990) 2 Con * <Member> 04(c) pt04 pt05 0.0 sqr(0.464146377838545) 2 Con * <Member> 05(c) pt05 pt06 0.0 sqr(0.464146377838546) 2 Con * <Member> 06(c) pt06 pt07 0.0 sqr(0.383095246542990) 2 Con * <Member> 07(c) pt07 pt08 0.0 sqr(0.301915332950701) 2 Con * <Member> 08(c) pt08 pt01 0.0 sqr(0.261008730199888) 2 Con * <Member> 09(c) pt01 pt09 1.0 sqr(0.689891161160713) 3 Obj * <Member> 10(c) pt02 pt10 1.0 sqr(0.665510875807512) 3 Con * <Member> 11(c) pt03 pt11 1.0 sqr(0.739256300739300) 3 Con * <Member> 12(c) pt04 pt12 1.0 sqr(0.908039523981026) 3 Con * <Member> 13(c) pt05 pt13 1.0 sqr(1.09882495341673) 3 Con * <Member> 14(c) pt06 pt14 1.0 sqr(1.14981051589702) 3 Con * <Member> 15(c) pt07 pt15 1.0 sqr(1.01049024008915) 3 Con * <Member> 16(c) pt08 pt16 1.0 sqr(0.813398015083213) 3 Con * <Member> 17(s) pt01 pt16 -1.0 sqr(0.930211225870888) 1 Con * <Member> 18(s) pt02 pt09 -1.0 sqr(0.849854394375223) 1 Con * <Member> 19(s) pt03 pt10 -1.0 sqr(0.877233805489365) 1 Con * <Member> 20(s) pt04 pt11 -1.0 sqr(1.00302205041128) 1 Con * <Member> 21(s) pt05 pt12 -1.0 sqr(1.15285087051696) 1 Con * <Member> 22(s) pt06 pt13 -1.0 sqr(1.21931486941198) 1 Con * <Member> 23(s) pt07 pt14 -1.0 sqr(1.19871926268034) 1 Con * <Member> 24(s) pt08 pt15 -1.0 sqr(1.08313829018149) 1 Con * <Member> 25(c) pt09 pt10 0.0 sqr(0.276112253335532) 2 Con * <Member> 26(c) pt10 pt11 0.0 sqr(0.256060301692048) 2 Con * <Member> 27(c) pt11 pt12 0.0 sqr(0.276112253335532) 2 Con * <Member> 28(c) pt12 pt13 0.0 sqr(0.338385830283023) 2 Con * <Member> 29(c) pt13 pt14 0.0 sqr(0.428933030260907) 2 Con * <Member> 30(c) pt14 pt15 0.0 sqr(0.477402187936063) 2 Con * <Member> 31(c) pt15 pt16 0.0 sqr(0.428933030260908) 2 Con * <Member> 32(c) pt16 pt09 0.0 sqr(0.338385830283022) 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): 0.261009 02(c): 0.301915 03(c): 0.383095 04(c): 0.464146 05(c): 0.464146 06(c): 0.383095 07(c): 0.301915 08(c): 0.261009 09(c): 0.689891 10(c): 0.665511 11(c): 0.739256 12(c): 0.90804 13(c): 1.09882 14(c): 1.14981 15(c): 1.01049 16(c): 0.813398 17(s): 0.930211 18(s): 0.849854 19(s): 0.877234 20(s): 1.00302 21(s): 1.15285 22(s): 1.21931 23(s): 1.19872 24(s): 1.08314 25(c): 0.276112 26(c): 0.25606 27(c): 0.276112 28(c): 0.338386 29(c): 0.428933 30(c): 0.477402 31(c): 0.428933 32(c): 0.338386 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): 0.373147 02(c): 0.325355 03(c): 0.257914 04(c): 0.210412 05(c): 0.210412 06(c): 0.257914 07(c): 0.325355 08(c): 0.373147 09(c): 0.689891 10(c): 0.714551 11(c): 0.644801 12(c): 0.526374 13(c): 0.433788 14(c): 0.413674 15(c): 0.472738 16(c): 0.58702 17(s): -0.723498 18(s): -0.788567 19(s): -0.765149 20(s): -0.672798 21(s): -0.585149 22(s): -0.549745 23(s): -0.560797 24(s): -0.623763 25(c): 0.353997 26(c): 0.379874 27(c): 0.353997 28(c): 0.291607 29(c): 0.229412 30(c): 0.20375 31(c): 0.229412 32(c): 0.291607 Average tendon force magnitude: 0.381256 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> 125 Strut and Tendon Hub Adjustments - s;t> 0 0 01(c): 32 0 02(c): 37 0 03(c): 47 0 04(c): 57 1 05(c): 57 1 06(c): 47 0 07(c): 37 0 08(c): 32 0 09(c): 83 0 10(c): 80 0 11(c): 89 1 12(c): 110 1 13(c): 134 1 14(c): 140 1 15(c): 123 1 16(c): 98 1 17(s): 116 1 18(s): 106 0 19(s): 109 1 20(s): 125 1 21(s): 144 0 22(s): 152 1 23(s): 150 0 24(s): 135 1 25(c): 34 0 26(c): 31 1 27(c): 34 0 28(c): 41 1 29(c): 53 0 30(c): 59 0 31(c): 53 0 32(c): 41 1 Material Quantities (in millimeters) Estimates of the total amount of material required to build the structure. The adjustment in this case includes "waste": for the strut, the amount lost when sawing the strut from a length of dowel (1 mm from each end); for the tendons, the amount of extra needed to successfully tie the tendon (20 mm extra at each end). Elongation of Tendon of Unit Cross Section Under Force of Average Magnitude (fraction)> .02 Length Scale Factor> 125 Strut and Tendon Adjustments - s;t> -1 -20 Cross Type Section Quantity Count 2 1 1325.31 16 3 1 1170.98 8 1 1 1055.29 8 Strts 1055.29 8 Tndns 2496.29 24
Perspective Prism with Point Labels
structure file: sk8prsm/stage6.rc variable file: sk8prsm/stage6.dat digit list: src/mm.dls |
CONTACT: Bob Burkhardt Tensegrity Solutions Box 426164 Cambridge, MA 02142-0021 USA e-mail: bobwb@juno.com |