Issue 53

R. M. Reda et al., Frattura ed Integrità Strutturale, 53 (2020) 106-123; DOI: 10.3221/IGF-ESIS.53.09

Effect of NSM Bar Number The effect of the NSM FRP bar number was shown in (Fig. 13), the figure clarify that the increasing of bar number in the strengthened beams from one bar to two bars increase the load carrying capacity of the strengthened beams, the load carrying capacity for beams 2G-0.5-50/90 and 1G-0.5-50/90 were 168.6 and 148.6kN with increasing of 86.2 and 64.1% respectively if compared with CB, using two bars instead of one bar increase the load carrying capacity by 13.5%, this result agree with this reported in [11], (Fig13-c) shows the same observation for the effect of NSM bar length on the strain of NSM FRP bars.

100 120 140 160 180 200

100 120 140 160 180 200

100 120 140 160 180 200

(a)

(c)

(b)

0 20 40 60 80

0 20 40 60 80

0 20 40 60 80

Load, (kN)

Load, (kN)

CB 1G‐0.5‐90/50 2G‐0.5‐90/50

Load, (kN)

CB 1G‐0.5‐90/50 2G‐0.5‐90/50

1G‐0.5‐90/50 2G‐0.5‐90/50

0

5

10

15

20

25

30

35

0

5

10

15

0

5

10

15

Strain, (microstrain x 10 3 )

Deflection, (mm)

Strain, (microstrain x 10 3 )

Figure 13: Effect of NSM bar number: (a) load-deflection curve, (b) steel strain and (c) FRP strain.

Bar Length 0.25L

Bar Length 0.5L

Bar Length 0.8L

Leg        Bar        angle     no;      

Leg        Bar     angle     no;    

1.60

1.60

Leg        Bar     angle     no;    

1.60

(b)

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

(a)

1.50

1.50

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

1.50

1.40

1.40

1.40

1.30

1.30

1.30

P u /P u,θ=0

P u /P u,θ=0

P u /P u,θ=0

1.20

1.20

1.20

(c)

1.10

1.10

1.10

1.00

1.00

1.00

0

50

100

150

0

50

100

150

0

50

100

150

Leg inclination length (mm)

Leg inclination length (mm)

Leg inclination length (mm)

Figure 14: The effect of NSM bar number on P u / P u, θ =0 for: (a) beams strengthened with bar length 0.8L, (b) beams strengthened with bar length 0.5L and (c) beams strengthened with bar length 0.25L.

Bar Length 0.25L

Bar Length 0.5L

Bar Length 0.8L

Leg        Bar       angle     no;     

Leg        Bar       angle     no;     

Leg        Bar            angle     no;       

0.50 0.70 0.90 1.10 1.30 1.50 1.70 1.90 2.10 2.30 2.50 2.70 2.90 3.10

0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20

0.50 0.70 0.90 1.10 1.30 1.50 1.70 1.90 2.10 2.30 2.50 2.70 2.90 3.10

(c)

(a)

45    1Bar 45    2Bars 60    1Bar 60    2Bars 90    1Bar 90    2Bars

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

Δ u /Δ u,θ=0

Δ u /Δ u,θ=0

Δ u /Δ u,θ=0

(b)

0

50

100

150

0

50

100

150

0

50

100

150

Leg inclination length (mm)

Leg inclination length (mm)

Leg inclination length (mm)

Figure 15: The effect of NSM bar number on Δ u / Δ u, θ =0 for: (a) beams strengthened with bar length 0.8L, (b) beams strengthened with bar length 0.5L and (c) beams strengthened with bar length 0.25L.

Bar Length 0.8L

Bar Length 0.25L

Bar Length 0.5L

Leg        Bar        angle     no;      

Leg        Bar        angle     no;      

Leg        Bar        angle     no;      

1 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.1

1 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.1

1 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.1

(b)

(a)

(c)

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

45    1 Bar 45    2 Bars 60    1 Bar 60    2 Bars 90    1 Bar 90    2 Bars

E/E θ=0

E/E  θ=0

E/E θ=0

0

50

100

150

0

50

100

150

0

50

100

150

Leg inclination length (mm)

Leg inclination length (mm)

Leg inclination length (mm)

Figure 16: The effect of NSM bar number on E / E θ =0 for: (a) beams strengthened with bar length 0.8L, (b) beams strengthened with bar length 0.5L and (c) beams strengthened with bar length 0.25L.

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