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> strut pt2 pt3 0.0 1.0 1 Con CalcClear Inelastic * <Member> triten pt1 pt2 0.0 sqr(1/3) 2 Con CalcClear * <Member> zzten pt1 pt5 1.0 0.0 3 Obj CalcClear * 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 screw-eye center to screw-eye center, as are the tendon lengths. The values are in model units. strut: 1 triten: 0.333333 zzten: 0.447433 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. strut: -0.456353 triten: 0.768471 zzten: 0.447433 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 a 5/16-inch-diameter wooden dowel. The tendons can be made of braided nylon fishing line. Prestress forces were assumed not to affect strut lengths. Elongation of Tendon of Unit Cross Section Under Force of Average Magnitude (fraction)> .02 Length Scale Factor> 212 Strut and Tendon Hub Adjustments - s;t> 7.5 3.5 (The 7.5 mm adjustment for the strut is the amount the screw-eye center extends from the dowel. The 3.5 mm adjustment for the tendon is half the outer diameter of the screw eye.) strut: 197 0 triten: 62 0 zzten: 86 1
Zig-Zag Tensegrity Cube with Point Labels
(The point labels coincide with the ones listed above.
There are some
extra labels as well for points that aren't listed above.)
structure file: cube/zigzag1.rc variable file: cube/zigzag1.dat digit list: src/mm.dls |
CONTACT:
Bob Burkhardt
Tensegrity Solutions
Box 426164
Cambridge, MA 02142-0021
USA
e-mail: bobwb@juno.com