Fatigue breakage

Figure 5.4 Different dispersion mechanisms for solid particles in viscous flow (a) rupture, (b) shattering, (c)(d) erosion of smaller fragments or individual particles, and (e) fatigue breakage [13]...

Breakage of an implanted joint is rare. Breakage occurs when the bone flexes and the metal implant does not flex as much, thereby exceeding its mechanical fatigue point causing the implant to break or crack. A revision joint replacement operation is necessary if breakage occurs. 

Shaft breakage and other fatigue failures in the pump. 

The valve plates, discs, and springs are mounted in a valve cage, which is inserted in the cylinder. Valve breakage occurs due to fatigue of the metal or improper action. This requires replacement and an evaluation of the materials of construction as well as the basic type of valve. Each manufecturer presents his valve design to match his equipment. Only experience can determine which type of valve works best in a given application... 

The results of the investigations concluded that the breakage of the thermocouple well was caused by the high frequency fatigue as a result of flow-induced vibration parallel to the direction of sodium flow. The thermocouple well broke at the point of reduction of radius. It has also been clarihed that the design of the thermocouple well was inadequate in that it did not take into account the phenomenon of parallel vibration. 

The change in properties extends beyond the static properties of the material. Under dynamic loading, the material behaves much more elastically and the tendency to destruction by hysteresis induced heating effects is reduced. On the other hand, because the polymer chains are stretched severely in the stress transfer process, there are much higher levels of bond breakage and recrystallization effects with typical fatigue failure performance. In the balance, the net result is a substantial improvement in the performance of the material in dynamic loading. 

In cases where elimination of agglomerates is essential to ensure that optimum compound properties are achieved, melt filtration can be used. This is important in pigment masterbatch production or in coloured compounds to be spun into fibres, where agglomerates can lead to fibre breakage. Removal of impurities or large defect particles by melt filtration can also increase the fatigue life of FIDPE pipe and the resistance to breakdown of polymer subjected to an electrical stress [71, 72]. 

Kozhushko and Kopnov [30] identify a number of possible failure modes for fabric conveyor belts. Abrasive wear, fabric breakage or joint failure are all possible failure modes but the failure mode of most interest here is that of fatigue delamination, and it is... 

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