PSI - Issue 18

Muhammad Fawad et al. / Procedia Structural Integrity 18 (2019) 189–197 M. Fawad/ Structural Integrity Procedia 00 (2019) 000–000

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this time we have to apply the calculated number of strips at the calculated distances. Loading, meshing, analysis steps and monitoring points will remain same for this model. The overall model is shown in the figure 3.2.1 Deflection Deflection value along x-axis obtained after the analysis are shown in the table 3, which shows that deflection has been reduced remarkably due to application of retrofitting using steel plates

Table 3- Deflections- FRP Strengthening

Section I & II

Z3 (Z-axis)

Critical Max (mm) Critical Min (mm)

2.74

-0.005

3.2.2 Cracks Total Area of cracked region = (9.6+7.28+4.04) = 20.92 m²/span= 20.92/414= 5%

Percentage cracked area has significantly reduced from 30% to 5%. These results show the advantage of using the FRP and their usability. Now the most critical parameter is the crack width because the bridge is not satisfying the allowable crack width limit in un-strengthened condition and even in case of steel plates, it is too close. After the application of FRP strips, it has been observed that the critical crack width at the central support has reduced to 0.035mm (Figure 5). Critical crack width has been reduced from 0.61mm to 0.034mm (table 4), which is much deeper in safety zone. These results also show the perfection of FRP strips.

Figure 5- Critical Crack Width- FRP Strengthening

Table 4- Table 16- Maximum Crack Width- FRP strengthening

Section I & II

(mm) 0.0346

Maximum crack width

3.2.3 Load-displacement Curve LD Curve show that at the maximum load, deflection value of 2.74 mm is recorded. Curve is showing that after the displacement of 0.75mm the load value bumps and reduces. This actually happened due to failure of some of the FRP strips, thus load bearing capacity reduces a bit but then the displacement value reaches to its maximum value till the maximum value of applied load.