Issue 72

M. A. M. Khalil, Fracture and Structural Integrity, 72 (2025) 263-279; DOI: 10.3221/IGF-ESIS.72.19

1400

1400

Ptheo FEA

Ppequ FEA

1241

1200

1220

1200

1109

1058

986

1121

1100

1016

1000

1061

1000

855

891

803

860

761

842

800

821

800

600

600

Pmax (kN)

Pmax (kN)

400

400

200

200

0

0

0.79%

1.23%

1.77%

3.14%

0.79%

1.23%

1.77%

3.14%

a) Conventional column b) Composite columns Figure 14: Effect of the reinforcement ratio on theoretical and numerical maximum axial load.

1400

P = 66.099 ρ + 1011 R2 = 0.9916

1200

1000

800

P = 28.635 ρ + 803.89 R2 = 0.9712

600

Load (kN)

400

Composite Columns Conventional Columns

200

0

ρ (%)

Figure 15: Relationship between reinforcement ratio and axial load.

GFRP dimensions (mm)

GFRP I-section ratio (%)

Stress in GFRP (MPa) 181.41 212.00 213.09 166.67 140.53 116.70 292.43 199.97 321.55 205.90 257.64 147.14

GFRP section

P FEM (kN)

Stress in steel (Mpa)

No.

P Equ (kN)

P FEM / P PEqu

RGFRP-P1 RGFRP-P2 RGFRP-P3 RGFRP-P4 RGFRP-P5 RGFRP-P6 RGFRP-I1 RGFRP-I2 RGFRP-I3 RGFRP-I4 RGFRP-I5 RGFRP-I6

89x5.5 84x8 80x10 76x12 70x15 60x20

2.03 2.88 3.52 4.13 4.98 6.25 5.35 7.63 9.38

899.91 940.08 970.55 999.52 1040.20 1058.35 1057.76 1165.96 1249.17 1329.42 1444.21 1578.45

935.00 998.75 1040.00 995.00 980.00 980.00 1100.00 1107.50 1178.75 1195.00 1197.50

1.04 1.06 1.07 1.00 0.94 0.93 1.04 0.95 0.94 0.90 0.83 0.77

349.05 400.00 400.00 362.04 359.82 301.61 400.00 400.00 400.00 400.00 400.00 338.93

Flat Plate

100x80x5.5 100x80x8 100x80x10 100x80x12 100x80x15 100x80x20

I-section

11.06 13.48 17.18

1210

Table 9: Effect of GFRP ratio on theoretical and numerical maximum axial load.

Effect of GFRP ratio To investigate the influence of the GFRP ratio on the behavior of RC composite columns, analyses were performed for twelve different values ranging from 2.03% to 17.18% using two different shapes of GFRP sections, flat plates and I-shaped sections. The concrete compressive strength was set at 40 MPa and steel yield strength was 400 MPa.

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