Civil Engineering Reference
In-Depth Information
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6.7.4.4 Results
The following outputs are depicted: deflected shape
(
Figure 6.11
); bending moments in the chord elements
(
Figure 6.12
); axial forces in the chord elements (
Figure 6.13
).
Loading on roof: Permanent Load G = 1.3 kN/m
2
Non-permanent load Q = 1.0 kN/m
2
Design load for quoted case w = 1.35G + 1.5Q
6.7.4.5 Model validation
Elasticity
6.7.4.3 The analysis model
Figure 6.10
shows a plane frame model of the truss.
Timber
: Acceptance criterion: design to code of practice.
Element types:
Chords and posts: Beam elements - bending and axial deform-
ation - with no shear deformation
Diagonals: Truss elements - only axial deformation, no
bending.
Section and material properties
are given in
Table 6.3
.
Steel wire:
Design to code of practice.
6.7.4.6 Element types
Beam elements for timber members:
Timber members and
connections to be designed to take combined axial forces and
moments predicted by the model.
28
24
30
32
26
34
36
8
9
10
11
12
13
14
9
10
11
12
13
19
14
20
15
21
16
22
24
16
26
28
18
30
32
34
36
15
17
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
33
23
35
25
27
31
29
Figure 6.10 Analysis model showing node and element numbers
9
9
14
16
9
15
10
13
15
22
23
10
25
12
35
11
11
14
16
21
12
18
13
24
2
33
17
20
32
8
1
1
7
29
19
6
2
7
3
5
4
6
3
4
5
Figure 6.11 Deflected shape
-3.454
-3.454
-1.543
-1.543
-3.467
9
-3.467
-0.524
-0.524
10
11
3
12
13
14
8
11
13
16
10
12
14
15
-1.535
-1.535
1.431
1.431
5
4
6
3
2
-0.316
2.316
7
1
4
5
2
3.373
6
7
8
3.373
1.431
1.431
2.313
2.313
3.388
3.388
Figure 6.12 Bending moments in chord elements
8
9
10
11
12
13
14
36.585
10
11
12
13
14
15
16
36.585
1
-96.517
-96.517
145.166
133.041
133.041
96.614
96.614
1
2
3
4
5
6
7
36.829
36.829
1
2
3
4
5
6
7
8
Figure 6.13 Axial forces in chord elements
