Fracture Mechanics Models for Brittle Failure of Bottom Rails due to Uplift in Timber Frame Shear Walls
Table 4
Measured failure loads and horizontal crack lengths for failure mode 2 for specimens with the pith oriented downwards (PU) for single- and double-sided sheathing. is the length of the horizontal crack before it changes direction. End 1 and End 2 indicate the two bottom rail ends.
(a) Study A
Series 1
Series 2
Series 3
Set 3
Set 4
Set 1
Set 2
Set 3
Set 1
Set 2
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
Single-sided
21.0
15
13
23.8
12
—
21.2
22
27
21.8
20
16
27.1
5
—
19.9
11
—
27.1
20
—
—
—
—
—
—
—
21.9
16
—
20.6
16
14
—
—
—
—
—
—
—
—
—
(b) Study B
Series 1
Series 2
Series 3
Set 3
Set 4
Set 1
Set 2
Set 3
Set 1
Set 2
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
Failure load [kN]
[mm]
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
End 1
End 2
Single-sided
—
—
—
—
—
—
—
—
—
17.1
—
18
26.3
26
13
16.5
12
—
—
—
—
—
—
—
—
—
—
—
—
—
15.4
—
17
25.5
—
22
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
19.7
22
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
22.2
—
12
—
—
—
—
—
—
Double-sided
34.1
17
—
32.4
—
20-20
—
37.4
14
—
38.0
23–15
—
—
—
—
50.0
—
10
—
—
—
37.8
22–16
—
—
—
—
39.5
—
10
—
—
—
39.0
—
23-23
—
—
—
43.8
21
—
—
—
—
35.3
—
16
Horizontal crack on both edges of the bottom rail. Uncertain whether failure was mode 2 or 3.