PSI - Issue 70

Alok Kumar et al. / Procedia Structural Integrity 70 (2025) 145–152

150

Table 5. Detail Result of a pushover Original structure

2 wrapping structure

4 wrapping structure

6 wrapping structure

DBE 0.263

MCE 0.315

DBE 0.264

MCE 0.313

DBE 0.264

MCE 0.312

DBE 0.265

MCE 0.312

Spectral acceleration (m/s 2 ) Spectral displacement (m) Base shear (kN) Time period (sec) Displacement (m)

0.06

0.182

0.094

0.18

0.093

0.178

0.091

0.176

Damping ratio 0.087

0.2

0.09

0.207

0.092

0.212

0.094

0.215

2653.937 3251.743 2659.062 3255.905 2664.114 3259.921 2670.293 3263.616

1.21

1.521

1.197

1.519

1.185

1.511

1.172

1.503

0.12

0.222

0.1180

0.221

0.116

0.217

0.114

0.214

The mode 1, mode 2, and mode 3 time periods decrease after wrapping. The increased global stiffness enhanced the stiffness of the structure. This shift in dynamic characteristics indicates an improved seismic response as the structure has higher natural frequencies. The symmetrical plan of the building mode 1 and mode 2 values is the same. The Mode 1 after 2 wrapping time periods decreased by 1.486%, 4 wrapping by 2.92%, and 6 wrapping by 4.24%. Mode 3 after 2 wrappings decreases by 1.51%, after 4 wrappings by 2.93%, and after 6 wrappings by 4.26%.

Time period

1.26664 0.8 1 1.2 1.4 Time period (sec )

1.26664

1.24758

1.24578

1.22972

1.22972

1.21289

1.21289

1.11393

1.08137

1.09713

1.06652

original structure

2 wrapping

4 wrapping

6 wrapping

mode 1 mode 2 mode3

Fig. 12. Time period of mode 1, mode 2 and mode 3 After retrofitting the maximum lateral displacement of the RC frame significantly decreases due to the increased stiffness. It enhanced the structural rigidity and improved energy dissipation reducing deformation under seismic loading. The DBE 2 wrapping displacement decreases 1.6%, 4 wrapping decrease 3.34 % and 6 wrapping 5 % decreases. The MCE 2 wrapping displacement decreased by 0.45%, 4 wrapping 2.25%, and 6 wrapping 3.61%.

Lateral displacement

0.5

0.12 .

0.221

0.222

0.217

0.214

0.118

0.114

0.116

0 original structure 2 wrapping CFRP 4 wrapping CFRP 6 wrapping CFRP Lateral displacement (m )

DBE MCE

Fig. 13. Result of lateral displacement