Very-high-cycle fatigue

S-N Response for Very-High-Cycle Fatigue (VHCF)... 

Figure 10.12. Schematic of the median characteristics for an alternative interpretation of the very-high-cycle fatigue S-N behavior [15].

S. Shirah, Y. Mutoh, K. Nagata Fretting Fatigue Behaviour of Ti-6AI-4V Alloy and Structural Steel in Very High Cycle Regime, University of Agricultural Sciences, 2001, p. 295-302... 

K. Shiozawa and L. Lu Very high-cycle fatigue behaviour of shot-peened high-carbon-chromium bearing steel. Fatigue and fracture of engineering materials and structures, 25(8) 813-833, 2002. 

Some recent developments concern very high-cycle fatigue behavior of austenitic stainless steels, up to 600°C [114]. As in-service conditions correspond to low strain amplitudes, experimental data are required for designing components. One of the main problems concerns the possible existence of the fatigue limit. 

On the other hand, very high temperatures and low cyclic loading frequencies (high cycle times) promote near-tip creep-fatigue conditions where... 

Fatigue-rotating cantilever bend test. very high (though different specimen each time) load - clear no. of cycles - clear very high medium - high... 

A load is applied further from the static load to maximum load with the help of the electro-hydraulic test rig, up to 3250 N, which is already obtained in static analysis. Test rig is set to operate for a deflection of 75 mm. This is the amplitude of loading cycle, which is very high. Frequency of load cycle is fixed at 33 mHz, as only 20 strokes/ min is available in the test rig. This leads to high amplitude low frequency fatigue test. 

Maximum and minimum stress values obtained at the first cycle of the CLS are 222 MPa and 133 MPa respectively. As the cycles go on increasing, stress convergence is happening only after 25000 cycles, lliese maximum and minimum operating stress values are 240 MPa and 140 MPa respectively. Because of very low stress level, fatigue life of CLS is very high under simulated conditions. 

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