Transcript スライド 1

2007 IUFRO All Division 5 Conference, Octorber 29th – November 2nd, 2007, Taipei
Strength Performance of Glulam made of
Obi-sugi Laminae with low
Young’s Modulus of Bending
Miyazaki Prefectural Wood Utilization Research Center
Akihiro Matsumoto, Hideki Morita, Yoshiyasu Fujimoto
Atsushi Shiiba, Yutaka Iimura
Miyazaki Prefectural Wood Utilization Research Center
About Miyazaki
Japan
Miyazaki
Miyazaki Prefectural Wood Utilization Research Center
About the standard of glulam in Japan
The standard of structural glued laminated timber (Glulam) is regulated by Japanese
Agricultural Standard (JAS) in Japan.
What’s the JAS?
The JAS is based on “The Law Concerning Standardization and Proper Labeling of
Agricultural and Forestry Products”.
The JAS standardize to regulate the quality of products, such as Agricultural,
forestry, livestock and marine products including manufactured or processed products.
The standard of laminae for
structural glulam in JAS
Grade by machine rating
Young’s modulus of bending
（GPa or 103N/mm2 ）
L200
L180
L160
L140
L125
L110
L100
L90
L80
L70
L60
L50
20.0
18.0
16.0
14.0
12.5
11.0
10.0
9.0
8.0
7.0
6.0
5.0
The standard of symmetric-structured
glulam composed of different grade of
laminae in JAS
Strength grade
E170-F495
E150-F435
E135-F375
E120-F330
E105-F300
E95-F270
E85-F255
E75-F240
E65-F225
Young’s modulus of bending
（GPa or 103N/mm2 ）
Ave
Lower limit
MOR
（MPa or
N/mm2）
17.0
15.0
13.5
12.0
10.5
9.5
8.5
7.5
6.5
14.0
12.5
11.5
10.0
9.0
8.0
7.0
6.5
5.5
49.5
43.5
37.5
33.0
30.0
27.0
25.5
24.0
22.5
Miyazaki Prefectural Wood Utilization Research Center
Laminae’s distribution chart
Specimens : Sugi(Japanese cedar) laminae grown in Miyazaki
40
About 30% of laminae shows
Young’s modulus less than
5.0GPa.
The yield of qualifying laminae
for structural glulam cut from
obi-sugi log is extremely low
and cost inhibited.
Examine how to effectively
utilize of lamina with low
Young’s modulus
30
Frequency(%)
These laminae will not meet
JAS standards.
: E ave
: E low
20
10
0
3
4
5
6
7
8
Laminae grade (GPa)
9
Figure.1 The influence of the evaluation method to
give it to MOE frequency distribution
(Number of samples : 5125)
*MOE was measured with grading machine, and each lamina
was classified by minimum MOE value in it
Miyazaki Prefectural Wood Utilization Research Center
Materials and methods
Miyazaki Prefectural Wood Utilization Research Center
lamina specimen
Five-grade machine stress
graded obi-sugi laminae
Grade by
machine rating
Young’s modulus
of bending
（GPa or 103N/mm2 ）
L70
L60
L50
L40
L30
7.0
6.0
5.0
4.0
3.0
JAS
laminae
Non JAS
laminae
3.8
0.51
Length
Width
Top Width
Bottom Width
Angle
Adhesive
Press pressure
： 14mm
： 3.8mm
： 0.51mm
： 0.3mm
： 1/9.4
： Water-base poly-isocyanate
resin adhesive
： 10MPa
14.0
Profile of the finger-joint
1/9.4
0.3
Diagram of finger-joint (unit:mm)
Miyazaki Prefectural Wood Utilization Research Center
Glulam specimen
E65-F225
inner laminae
grade is L50
E65
inner laminae
grade is L40
E55
inner laminae
grade is L40
E55
inner laminae
grade is L30
L80
L70
L60
L50
L50
L50
L50
L60
L70
L80
L80
L70
L60
L40
L40
L40
L40
L60
L70
L80
L70
L60
L50
L40
L40
L40
L40
L50
L60
L70
L70
L60
L50
L30
L30
L30
L30
L50
L60
L70
[JAS]
[nonJAS]
The standard of laminae for
structural glulam JAS
Grade by
machine rating
Young’s modulus
of bending
（GPa or 103N/mm2 ）
L200
L180
L160
L140
L125
L110
L100
L90
L80
L70
L60
L50
20.0
18.0
16.0
14.0
12.5
11.0
10.0
9.0
8.0
7.0
6.0
5.0
Figure.2 Set up for symmetric-structured glulam composed
of different grade of laminae including those with
lower Young's modulus
Miyazaki Prefectural Wood Utilization Research Center
Test method of laminae
1.Bending test [Bending test C in JAS]
Specimens dimension ：
Width:120mm, Thickness:30mm, Length:800mm
Test method ：
4 points bending test
Distance between loading points : 210mm、
Distance between fulcra : 630mm
Loading speed ： 5mm/min
Number of specimens : Each grade 130, Total 650
210
630
Miyazaki Prefectural Wood Utilization Research Center
Test method of laminae
2.Tensile test [Tensile strength test in JAS]
Specimens dimension :
Width:120mm, Thickness:30mm, Length:2,000
Number of specimens : Each grade 50, Total 250
500
1,000
500
180
3.Compression test [Strength test of structural lumber]
Specimens dimension :
Width:120mm, Thickness:30mm, Length:180mm
Number of specimens : Each grade 50, Total 250
30
Miyazaki Prefectural Wood Utilization Research Center
Test method of glulam
1.Bending test [Bending test A in JAS]
Specimens dimension :
Width :120mm, Thickness :300mm, Length :6,000mm
Test method : 4 points bending test
Distance between loading points :1,200mm
Distance between fulcra :5,400mm
Number of specimens :
Each type 8, Total 24
1,200
5,400
Miyazaki Prefectural Wood Utilization Research Center
Test method of glulam
2.Tensile test [Strength test of structural lumber]
Specimens dimension :
Width:105mm, Thickness:300mm, Length:2,000mm
Number of specimens :
Each type 12, Total 36
500
2,000
500
720
3.Compression test [Strength test of structural lumber]
Specimens dimention :
Width :120mm, Thickness :300mm, Length :720mm
Number of specimens :
Each type 8, Total 24
120
Miyazaki Prefectural Wood Utilization Research Center
Result
Miyazaki Prefectural Wood Utilization Research Center
Results of bending test for laminae
MOR(N/mm2)
60
The bending strength of L30 and L40
laminae were equal or over the standard
strength of L50 laminae in JAS
40
JAS Ave
JAS
20
Lower limit
:Average
(Max/Min)
: 5th%ile
0
L30 L40 L50 L60 L70
Laminae grade
Figure.3 MOR of sugi laminae for each grade
(Number of specimens : each grade 130, total 650)
5th% ile: Lower 5% exclusion limits of the distribution
assumed to be normal
Miyazaki Prefectural Wood Utilization Research Center
Results of compression test for laminae
Compression strength (N/mm2)
60
:Average
(Max/Min)
: 5th%ile
The compression strength of L30 and
L40 laminae were over the standard
strength of L50 laminae in JAS
40
20
0
Standard strength of structural
softwood lumber in JAS
L30
L40 L50 L60 L70
Laminae grade
Figure.4 Compression strength of sugi laminae
for each grade
(Number of specimens : Each grade 50, Total 250)
Miyazaki Prefectural Wood Utilization Research Center
Results of tensile test for laminae
Tensile strength (N/mm2)
50
:Average
(Max/Min)
: 5th%ile
40
The tensile strength of L30 and L40
laminae were over the standard strength
of L50 laminae in JAS
30
JAS Ave
20
10
0
JAS Lower limit
L30 L40 L50 L60
Laminae grade
L70
Figure.5 Tensile strength of sugi laminae
for each grade
(Number of specimens : Each grade 50, Total 250)
Miyazaki Prefectural Wood Utilization Research Center
Results of bending test for glulam
50
:Average
(Max/Min)
: 5th%ile
MOR(N/mm2)
40
The MOR of all glulam types were equal
or over the standard strength of E65-F225
glulam in JAS
30
Strength standard of
E65-F225 glulam in JAS
20
10
0
E65(L40)
E55(L40)
E55(L30)
Types of glulam
Figure.6 MOR of sugi glulam for each type
(Number of specimens : Each type 8, Total 24)
Miyazaki Prefectural Wood Utilization Research Center
Results of compression test for glulam
Compression strength (N/mm2)
50
:Average
(Max/Min)
: 5th%ile
40
The compression strength of all glulam
types were over the standard strength of
E65-F225 in Building Standard Law
Failure in the glulam began with a knot
and a finger-joint
30
20
Standard strength of E65-F225 glulam
in Building Standard Law
10
0
E65(L40)
E55(L40)
E55(L30)
Types of glulam
Figure.7 Compression strength of sugi glulam
for each type
(Number of specimen : Each type 8, Total 24)
Miyazaki Prefectural Wood Utilization Research Center
Results of tensile test for glulam
30
Tensile strength(N/mm2)
:Average
(Max/Min)
: 5th%ile
Some of the specimens were slightly
lower in tensile strength than that of
E65-F225.
20
10
0
Standard strength of E65-F225 glulam
in Building Standard Law
Most of the
specimens broke
close to where they
were chucked.
E65(L40)
E55(L40)
E55(L30)
Types of glulam
Figure.8 Tensile strength of sugi glulam
for each type
(Number of specimen : Each type 12, Total 36)
Miyazaki Prefectural Wood Utilization Research Center
Conclusion
Miyazaki Prefectural Wood Utilization Research Center
Strength Performance of Glulam made of Obi-sugi laminae
with low Young’s Modulus of Bending
Strength performance of laminae
The strength performances of laminae with lower Young’s modulus such as
L30 and L40 were nearly equal to that of sugi wood with Young’s modulus
of 5.0 kN/mm2.
Strength performance of glulam
As for the glulam made with composition of these lower Young’s modulus
laminae, such as E65(using L40 laminae for inner layer), E55(L40 for
inner layer) and E55(L30 for inner layer), the glulam performed well in
bending and compression tests.
Some specimens showed slightly lower tensile strength than that of E65-F225.
It seems to be necessary to examine the strength performance of glulam
made of laminae classified by average MOE value in it.
Miyazaki Prefectural Wood Utilization Research Center
Strength Performance of Glulam made of Obi-sugi Laminae
with low Young’s Modulus of Bending
Miyazaki Prefectural Wood Utilization Research Center