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TESTS ON WELDED GIRDERSIMPERFECTIONS

STABILITY BEHAVIOURLOAD-BEARING CAPACITYNUMERICAL MODELLING

Gábor JAKAB, PhD Student, BME

László DUNAI, Professor, BME

Robert T. Macdonald, Principal Eng., Lindab Butler Ltd.

Programme Imperfections Strength checking FE modellingBackground Conclusion

BME:Fabrication simulation – virtual fabricationBehaviour simulation – virtual tests

Background

LINDAB-BUTLER:Effect of single-sided fillet weld on

- imperfections- different failure modes

Programme Imperfections Strength checking FE modellingBackground ConclusionBackground

EXPERIMENTAL BACKGROUND IS NECCESARY

I-shaped plate girders with single-sided fillet weld

11 Large specimens (Length: 5970 mm)

• Imperfections

• Load bearing capacity

• Stability phenomena

18 Small specimens (Length: 2970mm)

• Residual stresses

• Load bearing capacity

• Stability phenomena

Effect of imperfections

Effect of single-sided fillet weld}Programme

} Effect of welding

Programme Imperfections Strength checking FE modellingBackground ConclusionProgramme

Specimen

Programme Imperfections Strength checking FE modellingBackground ConclusionImperfections

Temperature measurements

MOVING CAMERA

FIXED CAMERA


250

300

350

400

450

500

550

600

650

700

0 20 40 60 80 100 120 140 160 180 200T

em

pe

ratu

re (

C)

Time (sec)

L4BEAM

Tem

pera

ture

Time

Expected result

250

300

350

400

450

500

550

600

650

0 5 10 15 20 25 30 35 40 45 50

Te

mp

era

ture

(C

)

Time (sec)

I60x15/1

Tem

pera

ture

Time

Expected result

MOVING CAMERA FIXED CAMERA

Measurement results


Residual stress measurements


Flange (longitudinal)

-200

-150

-100

-50

0

50

100

150

-75 -55 -35 -15 5 25 45 65

Flange width [mm]

Mea

sure

d S

tres

s [M

Pa]

Middle, Single (I60x15S)

Middle, Double (I60x15D

End, M. Double (I60x15MV)

FILLET WELD

Measurement results


Imperfection measurements


Measurement resultsRaw data

Processed data1

2

3

4

5


Sections 1, 5

Sections2, 3, 4

Characterising imperfections

Sections2, 3, 4

OR

Section3

Using Fourier

Transformation

Defining wavelengths,

amplitudes of the waves

Sections 2, 3

Section 3


Loading frame

Test specimen

Measurementdevices

Hydraulic jacks

Test arrangement

Programme Imperfections Strength checking FE modellingBackground ConclusionStrength checking

Phenomenon – local buckling


Global phenomena


Local phenomena


Evaluation of test resultsTest

resistanceStandard-based

resistance

Plate buckling: ~1.18 – 1.20

LT buckling: ~1.40 – 1.80

Shear buckling: ~2.20

Web crippling: ~1.10 – 2.00


Numerical model

Geometrical measurements

Programme Imperfections Strength checking FE modellingBackground ConclusionFE modelling

Imperfect geometry based on Eigenvalue analysis

EC3 Part 1.5, Annex C

Test result

Numerical model

Programme Imperfections Strength checking FE modellingBackground ConclusionFE modelling

FE results fordifferent shapesof imperfections

EC3, LT buckling

Conclusions

• Local and global failure modes have been investigated on thespecimens.

• No direct effect of the single-sided fillet weld on the load-bearingcapacity of the specimen was observed.

• Satisfactory safety of the specimen – with significant differences fordifferent failure modes – was obtained.

• Geometrical imperfections and residual stresses of specimen fabricatedwith single-sided fillet weld were measured.

• A FE model was introduced; effect of different imperfection shapes wereinvestigated by nonlinear simulation.

Programme Imperfections Strength checking FE modellingBackground ConclusionConclusion

Thank you forYour attention!

Programme Imperfections Strength checking FE modellingBackground Conclusion

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