Vibration-fatigue methods offer a more effective approach, which estimates fatigue life in many points on the structure and successfully predict where the failure will most probably occur.
42.
Increases in fatigue life and strength are proportionally related to the depth of the compressive residual stresses imparted by surface enhancement processes such as shot peening but particularly by laser peening.
43.
In December 1971, the last of the RAF's Sycamores were officially retired; this had been due to critical parts having reached the end of their fatigue life.
44.
The simulation continued for another year to complete the engine fatigue life test and crack propagation studies for a damage tolerance analysis program of conducted by Embraer and IAE / ASA.
45.
Depending on the part geometry, part material, shot material, shot quality, shot intensity, and shot coverage, shot peening can increase fatigue life up to 1000 %.
46.
This research explored the in-material effects in more depth and demonstrated the creation of deep compressive stresses and the accompanying increase in fatigue and fretting fatigue life achieved by laser peening.
47.
Inspections of the entire fleet showed that the wing spars were suffering from fatigue at between 35 % and 75 % of the assessed safe fatigue life, probably due to low level turbulence.
48.
The fatigue life of an extreme performance spring ( NHRA, IHRA ) can be as short as two passes on a 1 / 4 mile drag racing track before relaxation or failure occurs.
49.
F L is taken between 2.5-3 generally as to correspond to a nominal fatigue life of 11, 000-20, 000 hours as part of a usual design.
50.
Engineers have used any of three methods to determine the fatigue life of a material : the stress-life method, the strain-life method, and the linear-elastic fracture mechanics method.
