The greater proportion of fractures of engineering components in service display evidence of fatigue crack propagation. Although the fractures are referred to as fatigue failures, it is shown by example that the true causes are: (1) neglect of cyclic service loading; (2) resonant vibrations; (3) increase in service cyclic loadings due to wear or maloperation; (4) material defect; (5) sharp notches; (6) welds and unsound surface deposits; and (7) corrosion or fretting fatigue.
Many breakdowns caused by failures involving one or more of these causes could have been avoided at the design stage or during manufacture, operation, or repair of the affected parts.
Get full access to this article
View all access options for this article.
References
1.
Report of the inquiry into the causes of the accident to the drilling rig Sea Gem, 1967 (September) (H.M.S.O.).
LuckG. A.‘Role of blade vibration failures in improving steam turbine reliability’, Engineer1963 (25th October), 674.
4.
SmithD. M.‘Vibration of turbine blades in packets’, Proc. Seventh Int. Congress Applied Mechanics 1948 (September).
5.
KantorowiczO. P. T.‘Of steam turbine wheel, batch and blade vibrations’, Trans. NE. Coast Instn Engrs Shipbldrs196279, 52.
6.
‘Redesign stops connecting rod failures’, Engineering1959 (25th December), 685.
7.
SchusterL. W.‘Investigation of the mechanical break-down of prime movers and boiler plant’, Proc. Instn mech. Engrs1933124, 337.
8.
FieldJ. E.WatersD. M.‘The fretting-fatigue strength of a 100 ton/in2 En 30B steel’, N.E.L. Rept No. 340 1968 (January).
9.
FieldJ. E.WatersD. M.‘Fretting-fatigue strength of En 26 steel—effect of mean stress, slip range and clamping conditions’, N.E.L. Rept No. 275 1967 (February).
10.
GurneyT. R.Fatigue of welded structures1968, 178 (Cambridge University Press).
