PSI - Issue 19

Sandro Citarelli et al. / Procedia Structural Integrity 19 (2019) 336–345 Sandro Citarelli, Markus Feldmann / Structural Integrity Procedia 00 (2019) 000 – 000

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2. Field investigations on crane runway girders under heavy service conditions

2.1. Data collection

A total of 66 crane runway girders of large dimensions which were built between 1965 and 1980 for the use in German steel works were examined. Depending on the production area, they experienced very high and almost continuous stresses during their operating period with load cycles generally well above 2 million, see Table 2. At the same time, with the exception of three girders from production area 4 and 5, they show no fatigue-related damage in the area of the upper weld which could be attributed to concentrated wheel load introduction.

Table 2. Overview of investigated runway beams Steelwork Production area Number of girders

Wheel loads [kN]

Span widths [m]

Number of wheels

Year of construction

Damage

Number of cycles N [x 10 6 ]

155 – 650

25 – 36

8 – 10

1

1

10

14

1976

no

90 – 595

10 – 20

2

8

36

12

1960

no

135 – 405

12 – 18

2 – 14

2

3

11

8

1965

no

225 – 560

15 – 16

4

4

12

4

1965

yes

290 – 480

3

5

1

18,5

4

1970

yes

74

200 – 740

12 – 39

6 – 24

4

6

15

12

1982

no

205 – 690

12 – 27

12 – 36

7

17

12

1982

no

Sum:

66

All girders are single spanned with spans widths between 12 m and 39 m. Compared to low- and medium-loaded crane girders, they have very large cross-sectional dimensions with cross-sectional heights of up to 5 m and sheet thicknesses of up to 90 mm. Fig. 3 shows an example of the weld execution of girders from production area 3 as described in Fig. 2. All top flange to web connections were executed with full penetrated welds (roots removed), even though numerous weld defects were found after dismounting and inspection, see Fig. 5. 85 % of the girders were executed using K welds with double fillet welds (two-sided) and 15 % with HV welds with counter-welded fillet welds (one-sided).

Fig. 2. Exemplary investigated crane runway beam from practice: longitudinal view (left) and cross section (right)