High-Cycle Fatigue Tests

When constant stress (5) amplitudes are encountered, the process is known as high cycle fatigue, because failure generally occurs only when N exceeds 10 cycles. Data from high cycle fatigue tests are reported in the form of an 5 vs Ai curve, as shown in Figure 4b (7). 

High cycle fatigue testing, 13 489-491 High density cleaning, in paper recycling, 21 436... 

In the case of a cracked component a crack analysis should be run to verify that the crack is a high cycle fatigue failure. An instrumented operational test of the component will identify the frequencies of high vibration levels causing the problem. 

Table la.25 High cycle fatigue strength of hip endoprostheses of stainless steel, measured in 0.9% NaCl solution at 37°C. Testing conditions according to DIN 58840 (simulation of a loosened shaft) (Ref. 19)... 

Mechanical low-cycle fatigue tests were performed (Ref 27) on several ICA joints and measured the resistance changes with high-sensitive micro-ohm technique. The resistance was observed to increase apparently at the initial stage of the tests, while the force required for the same deformation amplitudes decreased gradually. The authors attributed this phenomenon to the formation of wear tracks from filler frictions. However, they insisted that the influence of filler motion is limited and the dominant failure mechanism is interfacial fracture of the joint. 

Fig. 1.68 Fatigue IT-CT specimens tested in linear elastic (high-cycle fatigue) and elastic-plastic regime (low-cycle fatigue) from left to wright. Shear lips, not present in specimens 9 and 2, appear and develop specimens 15, 16 and 18 [108]...

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