PSI - Issue 10

Alk. Apostolopoulos et al. / Procedia Structural Integrity 10 (2018) 49–58 Alk. Apostolopoulos and T. Matikas / Structural Integrity Procedia 00 (2018) 000 – 000

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6

Table 7. Mechanical properties and life expectancy of Φ 12, B500A – 45 days corroded.

Sample

Free length

Strain ( % )

Max stress ( MPa ) 538.9

Stress at min strain ( MPa )

Force at min strain ( kN )

Min stress ( MPa ) -527.3

Min force ( kN ) -59.6

Cycles to failure

Dissipated energy ( MPa )

Mass loss ( % )

6 Φ

Mean value B500A 21-23 Mean value B500A 1-3 Mean value B500A 4-6 Mean value B500A 10, 30, 40

-508.3

-57.5

25

532.6

3.70

±2.5%

8 Φ

538.3

-410.3

-46.4

-506.7

-57.3

13

235.2

3.60

8Φ

544.7

-318.0

-36.0

-490.3

-55.4

7

187.6

3.64

±4%

6 Φ

547.1

-486.9

-55.1

-512.5

-58.0

8

279.2

4.00

Mean value 3.73

Table 8. Mechanical properties and life expectancy of Φ 12, B500A – 90 days corroded.

Sample

Free length

Strain ( % )

Max stress ( MPa ) 520.5

Stress at min strain ( MPa )

Force at min strain ( kN )

Min stress ( MPa ) -509.3

Min force ( kN ) -57.6

Cycles to failure

Dissipated energy ( MPa )

Mass loss ( % )

6 Φ

Mean value B500A 36-39, 20 Mean value B500A 11-14 Mean value B500A 15-19 Mean value B500A 31-35

-480.7

-54.4

15

304.4

8.43

±2.5%

8 Φ

539.1

-357.5

-40.4

-485.3

-54.9

12

192.9

7.85

8 Φ

541.0

-272.2

-29.6

-462.5

-51.7

6

160.4

7.65

±4%

6 Φ

531.2

-398.7

-45.1

-496.2

-56.1

6

212.1

10.2

Mean value 8.50

(b)

(a)

500

500

0

0

Stress [MPa]

Stress [MPa]

-500

-500

4

4

2

2

Strain [%] 0

Strain [%] 0

-2

-4

-2

-4

Fig 1. Impact of buckling on cyclic stress ( a) Representative Hysteresis loop comparison on a 8 Φ length bar of ε = ±2,5% and ε =±4%; (b) Representative Hysteresis loop comparison on a 6 Φ length bar of ε = ±2,5% and ε =±4%.