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Zig-Zag Ten-Stage Tensegrity Torus Datasheet


Copyright © 2003-2004 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.

<Member> st13a pt1A  pt3c   0.0  sqr(2.5)  1 Con CalcClear Inelastic *
<Member> st24a pt2A  pt4a   0.0  sqr(2.5)  1 Con CalcClear Inelastic *

<Member> guy1a pt1A  pt3b   1.00 0.0       3 Obj *
<Member> guy2a pt2A  pt4b   1.00 0.0       3 Obj *

<Member> TS23a pt2A  pt3a   0.0  sqr(1.0)  2 Con *
<Member> tS23a pt2A  pt3b   0.0  sqr(1.0)  2 Con *

<Member> tT31a pt3a  pt1C+  2.40 0.0       3 Obj *
<Member> tT42a pt4a- pt2C   2.40 0.0       3 Obj *

<Member> TS41a pt4a  pt1B+  0.0  sqr(1.0)  2 Con *
<Member> tS41a pt4a  pt1C+  0.0  sqr(1.0)  2 Con *

<Member> st13b pt1B  pt3a   0.0  sqr(2.5)  1 Con CalcClear Inelastic *
<Member> st24b pt2B  pt4b   0.0  sqr(2.5)  1 Con CalcClear Inelastic *

<Member> guy1b pt1B  pt3c   1.00 0.0       3 Obj *
<Member> guy2b pt2B  pt4c   1.00 0.0       3 Obj *

<Member> TS23b pt2B  pt3b   0.0  sqr(1.0)  2 Con *
<Member> tS23b pt2B  pt3c   0.0  sqr(1.0)  2 Con *

<Member> tT31b pt3b  pt1A+  2.40 0.0       3 Obj *
<Member> tT42b pt4b- pt2A   2.40 0.0       3 Obj *

<Member> TS41b pt4b  pt1C+  0.0  sqr(1.0)  2 Con *
<Member> tS41b pt4b  pt1A+  0.0  sqr(1.0)  2 Con *

<Member> st13c pt1C  pt3b   0.0  sqr(2.5)  1 Con CalcClear Inelastic *
<Member> st24c pt2C  pt4c   0.0  sqr(2.5)  1 Con CalcClear Inelastic *

<Member> guy1c pt1C  pt3a   1.00 0.0       3 Obj *
<Member> guy2c pt2C  pt4a   1.00 0.0       3 Obj *

<Member> TS23c pt2C  pt3c   0.0  sqr(1.0)  2 Con *
<Member> tS23c pt2C  pt3a   0.0  sqr(1.0)  2 Con *

<Member> tT31c pt3c  pt1B+  2.40 0.0       3 Obj *
<Member> tT42c pt4c- pt2B   2.40 0.0       3 Obj *

<Member> TS41c pt4c  pt1A+  0.0  sqr(1.0)  2 Con *
<Member> tS41c pt4c  pt1B+  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
        screw-eye center to screw-eye center, as are the tendon lengths.
        The values are in model units.

    st13a:          2.5     st24a:          2.5     guy1a:      2.08701
    guy2a:      1.76112     TS23a:            1     tS23a:            1
    tT31a:     0.593656     tT42a:      0.93513     TS41a:            1
    tS41a:            1     st13b:          2.5     st24b:          2.5
    guy1b:      2.43311     guy2b:      2.43311     TS23b:            1
    tS23b:            1     tT31b:      0.93513     tT42b:     0.593656
    TS41b:            1     tS41b:            1     st13c:          2.5
    st24c:          2.5     guy1c:      1.76112     guy2c:      2.08701
    TS23c:            1     tS23c:            1     tT31c:      1.19033
    tT42c:      1.19033     TS41c:            1     tS41c:            1


        Relative Member Prestress 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.

    st13a:     -3.86295     st24a:     -5.38353     guy1a:      2.08701
    guy2a:      1.76112     TS23a:      3.63978     tS23a:      2.20898
    tT31a:      1.42478     tT42a:      2.24431     TS41a:       2.9384
    tS41a:      2.20898     st13b:     -5.46398     st24b:     -5.46398
    guy1b:      2.43311     guy2b:      2.43311     TS23b:       2.9384
    tS23b:       3.0366     tT31b:      2.24431     tT42b:      1.42478
    TS41b:      3.63978     tS41b:      3.20531     st13c:     -5.38353
    st24c:     -3.86295     guy1c:      1.76112     guy2c:      2.08701
    TS23c:       2.0248     tS23c:      3.20531     tT31c:       2.8568
    tT42c:       2.8568     TS41c:       2.0248     tS41c:       3.0366

        Average tendon force magnitude: 2.48842


        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 5/16-inch-diameter wooden dowel.
        The tendons were 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> 238/2.5
        Strut and Tendon Hub Adjustments - s;t> 4 3.5
        (The 4 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.)

 
    st13a: 230 0     st24a: 230 0     guy1a: 188 1     guy2a: 158 1
    TS23a:  85 1     tS23a:  86 1     tT31a:  49 0     tT42a:  80 1
    TS41a:  86 0     tS41a:  86 1     st13b: 230 0     st24b: 230 0
    guy1b: 220 1     guy2b: 220 1     TS23b:  86 0     tS23b:  86 0
    tT31b:  80 1     tT42b:  49 0     TS41b:  85 1     tS41b:  86 0
    st13c: 230 0     st24c: 230 0     guy1c: 158 1     guy2c: 188 1
    TS23c:  87 0     tS23c:  86 0     tT31c: 104 0     tT42c: 104 0
    TS41c:  87 0     tS41c:  86 0

axial view of tensegrity torus
Axial View of the Ten-Stage Tensegrity Torus
with Point Labels

Schematic for the Tensegrity Torus
Schematic for the Tensegrity Torus

oblique view of tensegrity torus hovering over a landscape
Ten-Stage Tensegrity Torus Hovering Over
Shirley Center, Massachusetts

structure file:  torus/x3l10torus1.rc
 variable file:  torus/x3l10torus1.dat
    digit list:  src/mm.dls

CONTACT:

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

e-mail: bobwb@juno.com

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