Tri-5
spaceframe: (three-way
large and small triangular outer grid staggered over three- |
way hexagonal inner grid) |
. |
The
Tri-5 spaceframe lattice is basically the same as Tri-3 except that three struts
are also |
removed
periodically from the outer layer so as to form a grid of large and
small triangles. |
. |
 |
 |
 |
click image to enlarge |
a) outer grid |
b) inner grid |
c) strut diagram |
. |
Fig. 241 - Tri-5 spaceframe
[demonstration model constructed from
small triangles (ST) ]* |
|
* can also be constructed from RT, LT, or IT |
. |
The loss
of the struts in the outer layer further destabilizes the structure as
shown in the |
following unit cell analysis. |
|
|
|
Fig. 242 - Stability analysis |
of the Tri-5 unit cell |
|
(demonstration model) |
click image to enlarge |
|
a) M = 24 J = 12 |
b) stabilized by |
|
24 < 3 ( 12 ) - 6 |
plate action |
|
unstable, need +6 M |
(2 plates - red, blue) |
|
|
. |
Fig. 242 b) above shows that the spaceframe can stabilized by inserting panels or
skylights |
into the
large triangular openings of the outer layer (shown in blue) and the
hexagonal |
openings
of the inner layer (shown in red). |
. |
Due to the openness of the design, the Tri-5 spaceframe is |
 |
useful for atrium skylights and other
short and medium span |
applications. |
|
Fig. 243 - Patio table with Tri-5 spaceframe
sunshade ► |
(scale visualization model) |
click image to enlarge |
|
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Back
to Knowhere |
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Page 139
- Building stability - Tri-5 spaceframe |
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