PSI - Issue 62

Rossella Venezia et al. / Procedia Structural Integrity 62 (2024) 796–808 Rossella Venezia and Alessio Lupoi / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 11. Assumed modal shape in x direction “+” .

Fig. 12. Assumed modal shape in x direction “ - ” .

4.2. Reference point and target displacement

Five different reference points has been chosen, as described before. The assumed reference point is the joint of the left-side of the deck, that is the fixed side in the support scheme. It is the deck joint on the right-side of the pier. In the displacement-controlled pushover analysis it is required to choose the joint whose displacement is monitored, so-called control joint of the analysis. It is possible to carry out an analysis with any control joint and create the pushover curve using the extracted step-by-step displacements of a different joint, that is the reference point. For simplicity, five pushover analysis with five different control joints are carried out, one for each chosen reference point. They are carried out for each of the four load distributions described before. The results of pushover analyses are shown in Fig. 13 and in Fig. 14.

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niformshape (+) niformshape (+) 2 niformshape (+) niformshape (+) 0 niformshape (+)

0 000 000 2000 000

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niform shape ( ) niformshape ( ) 2 niform shape ( ) niformshape ( ) 0 niform shape ( )

Base hear k

Base hear k

0.00 0.02 0.0 0.0 0.0 0. 0 0. 2 0. 0. 0.

0.02 0.00 0.02 0.0 0.0 0.0 0. 0 0. 2 0. 0. 0.

ori . isp m

ori . isp m

Fig. 13. Influence of assumed reference point on the pushover curve: uniform shapes in direction “+” (left) and “ - ” (right)

In each of the five pushover analyses with uniform shape in direction “+” load distribution, first limit condition is reached in the plastic hinge at the bottom of no. 10 pier, because the demand chord rotation exceeds the capacity one. In the analysis with uniform shape in direction “ - ” load distribution, it is reached again in the plastic hinge at the bottom of no. 10 pier for capacity chord rotation achievement.

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20000 2 000 2 000 2000

0 000 000 2000 000

0 000 000 2000 000

odal shape (+) odal shape (+) 2 odal shape (+) odal shape (+) 0 odal shape (+)

odal shape ( ) odal shape ( ) 2 odal shape ( ) odal shape ( ) 0 odal shape ( )

Base hear k

Base hear k

0.02 0.00 0.02 0.0 0.0 0.0 0. 0 0. 2 0. 0. 0.

0.00 0.02 0.0 0.0 0.0 0. 0 0. 2 0. 0. 0.

ori . isp m

ori . isp m

Fig. 14. Influence of assumed reference point on the pushover curve: modal shapes in direction “+” (left) and “ - ” (right)