Fatigue properties, high performance

Fig. 2-45 Summary of high-performance fatigue properties of different materials based on their percent of ultimate static tensile strength.

Figure 7.25 High performance fatigue properties of RPs and other materials...

Recognize that with the many varying properties of the different RPs, there are those that meet high performance requirements such as long time creep resistance, fatigue endurance, toughness, and so on. Conversely, there are RPs that is volume and low cost driven in their use. As explained in this book, each of the different materials reqviires their specific RP processing procedures. 

Finally, there is a property of high-performance carbon fibers, both PAN and mesophase pitch-based, which sets them apart from other materials. They are not subject to creep or fatigue failure. These are important characteristics for critical applications. In a comparison of materials for tension members of tension leg platforms for deep-.sea oil production de.scribed by Salama (1997), carbon fiber strand survived 2,000,000 stress cycles between 296 and 861 MPa. In comparison, steel pipe stressed between 21 and 220 MPa failed after 300,000 cycles. Creep studies on PAN and... 

Although nanocomposites have been marketed as materials presenting superior mechanical performance, in some cases the wear and fatigue properties of composites containing nanoparticles were similar or worse than microfilled composites [4], Additional studies, nevertheless, report that dental nanocomposites present high translucency, high polish and polish retention similar to those of microfilled composites, while maintaining physical properties and wear resistance equivalent to those of several hybrid composites [5]. 

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