Low-cycle fatigue strength

In the 1980s, IN 738 blades were widely used. IN-738, was the acknowledged corrosion standard for the industry. New alloys, such as GTD-111, were developed and patented by GE in the mid-1970s. GTD-111 possesses about a 35 °F (20 °C) improvement in rupture strength as compared to IN-738. GTD-111 is also superior to IN-738 in low-cycle fatigue strength. 

Kagan, V. A., Palley, L, Nanjing, J. Plastics part design Low cycle fatigue strength of glass-fiber-reinforced polyethylene terephthalate (PET). J. Reinforced Plastics Compos. 23 (2004) 15, 1607-1614. 

Krempl, E., Low cycle fatigue strength reduction in notched flat plates, ASME Paper 67-MET-13, ASME, 1967. 

Low-cycle fatigue strength of beta processed Ti-5522-S depends on temperature, fi equency and the size of alpha platelets (see figure). 

High strain—Low cycle fatigue is strain-governed and occurs mainly in lower-strength/high-ductile materials. 

Here Sy is the yield strength of the material at the mean value of the temperature of the cycle and is the value obtained from the applicable design fatigue curve for the specified number of cycles of the condition being considered. The use of Eq. (11.1) is recommended for local thermal stresses only. Such an approach with a modified expression for Poisson s ratio involving the secant modulus, Eg has been employed in low cycle fatigue evaluation by Gonyea and Moulin and Roche. In their assessments the Poisson s ratio expression is represented as... 

High- and low-cycle fatigue data for smooth and notched specimens of Ti-6211 tested in air and in salt water exhibited a decrease in the fatigue strength for notched specimens at all cychc hves. The Severn River salt water, however, had no significant detrimental effect. The notch effect was... 

Equiaxed a Strength Ductility Fatigue Initiation Resist. Low Cycle Fatigue Resist. Fracture Tbughness Fatigue Crack Growth Resist. Notched Fatigue Resist. 

Coarse prior P grains Fracture Tbughness Creep Strength DuctOity Low Cycle Fatigue Resist. Fatigue Initiation Resist. 

---