Make your own free website on Tripod.com

Datasheet for Aspension Skylon II


Copyright © 2008 by Bob Burkhardt

        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.

# struts
<Member> struta      pb1' pa1  -1.0      sqr(0.60)  1 Con *
<Member> strutc1     pc2' pc1  -1.0      sqr(0.60)  1 Con *
<Member> strutc2     pc3' pc2  -1.0      sqr(0.60)  1 Con *
<Member> strutc3     pc1' pc3  -1.0      sqr(0.60)  1 Con *

# interlayer tendons
<Member> xltc1       pc1' pc1   1.0      0.0        3 Obj *
<Member> xltc2       pc2' pc2   1.0      0.0        3 Obj *
<Member> xltc3       pc3' pc3   1.0      0.0        3 Obj *
<Member> xltb1       pb1' pc1   1.0      sqr(0.25)  3 Con *
<Member> xltb2       pb1' pc2   1.0      sqr(0.25)  3 Con *
<Member> xltb3       pb1' pc3   1.0      sqr(0.25)  3 Con *
<Member> xlta1       pa1  pc1   1.0      sqr(0.55)  3 Con *
<Member> xlta2       pa1  pc2   1.0      sqr(0.55)  3 Con *
<Member> xlta3       pa1  pc3   1.0      sqr(0.55)  3 Con *

# end tendons
<Member> endc1'      pc2' pc1'  1.0      sqr(0.58762079226) 4 Con *
<Member> endc2'      pc3' pc2'  1.0      sqr(0.58762079226) 4 Con *
<Member> endc3'      pc1' pc3'  1.0      sqr(0.58762079226) 4 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.

   struta:          0.6   strutc1:          0.6   strutc2:          0.6
  strutc3:          0.6     xltc1:     0.301195     xltc2:     0.301195
    xltc3:     0.301195     xltb1:         0.25     xltb2:         0.25
    xltb3:         0.25     xlta1:         0.55     xlta2:         0.55
    xlta3:         0.55    endc1':     0.587621    endc2':     0.587621
   endc3':     0.587621

        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.

   struta:    -0.641147   strutc1:         -0.6   strutc2:         -0.6
  strutc3:         -0.6     xltc1:     0.301195     xltc2:     0.301195
    xltc3:     0.301195     xltb1:     0.534289     xltb2:     0.534289
    xltb3:     0.534289     xlta1:     0.235087     xlta2:     0.235087
    xlta3:     0.235087    endc1':     0.229129    endc2':     0.229129
   endc3':     0.229129

        Average tendon force magnitude: 0.324925

        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> 100/0.6
        Strut and Tendon Hub Adjustments - s;t> 0 0

   struta: 100 0   strutc1: 100 0   strutc2: 100 0   strutc3: 100 0
    xltc1:  49 1     xltc2:  49 1     xltc3:  49 1     xltb1:  40 1
    xltb2:  40 1     xltb3:  40 1     xlta1:  90 1     xlta2:  90 1
    xlta3:  90 1    endc1':  96 1    endc2':  96 1    endc3':  96 1

pedagogic view of aspension skylon
Aspension Skylon II with Point Labels

structure file:  marcus/x3l2marcuse.rc
 variable file:  marcus/x3l2marcuse.dat
    digit list:  src/mm.dls

CONTACT:

Bob Burkhardt
Tensegrity Solutions
Box 426164
Cambridge, MA 02142-0021
USA

e-mail: bobwb@juno.com

Back to Jan Marcus' Aspension Tower

More Datasheets