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A failure criterion for fillet welds

The work constitutes a study of the strength of mild steel fillet welds subject to static loading, and the behaviour of flange welded beam-column conne ct ions under comb ined bending an d shear. Tests are conducted on short \...;elds in the as-\...;elded and stress relieved conditions, and also on full-size beam-column connections. It is shown that welds under compression have a lower strength than when under tension. Failure of the fillet weld is initiated at the ,veld root, the important factor controlling the initiation being weld ductility. The greater the residual stress, the lower the weld ducti li ty and ul tilllate strength. The rmal st ress re lievi n g increases st rength by as much as 30%. Weld failure plane is rarely at the throat and varies from 0° to 45° depending upon loading condition. Failure plane average stresses are related by a circular function which is expressed in terms of externally applied forces at limit state. The tension weld of a flange-welded beaJll-column cOIlnection always fails before the compression \veld. The shear load sharing betlveen the welds is a complex function of elastic compression of the web, elastic/plastic deformation of the flanges, load/defonnation characteristics, and the type of load application. Bearing forces between the compression flange and column face produce low level bearing stresses and fri ctional forces which make a negligible contribution to shear- load resistance. Three modes of connection failure are possible; 'end mode', 'bending mode' and 'shear mode', with a sudden change taking place between the two latter.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:257496
Date January 1981
CreatorsHiggs, J. D.
PublisherAston University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://publications.aston.ac.uk/14227/

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