Paris-Erdogan equation

Paris [75] showed in 1964 that a linear relationship predicted by a simple power law for a double-logarithmic scale exists between the FCP rate da/dN and the applied AK (Fig. 6). The linear dependence is frequently observed only over an intermediate range of growth rates. On the double-logarithmic scale, the region of stable crack growth is usually satisfactorily described by the Paris-Erdogan equation... 

Region II The plot is linear and the crack growth rate can be described by the following equation (sometimes called the Paris-Erdogan equation) ... 

Fatigue Crack model The FCG model is constructed based on the popular Paris-Erdogan equation to express the crack growth rate ... 

Paris-Erdogan equation varies from 3.23 to 3.94 as in carbon steels or aluminum alloys, but the value of the constant C reaches a value among the lowest of them all... 

This, in practice, is worth a reduction of the RCCF, daldN. As such. Fiber proposed a modified Paris-Erdogan equation... 

The two non-dimensional functions F and Q, whose expression are given in Appendix A, depend on the crack size a as shown in the diagram of Fig. 11.40. This means the explicit integration of the Paris-Erdogan equation is rather difficult. It will be used the finite difference integration approach. 

Taking into account both the surface wear and crack tip advance rate (which may be defined using the Paris-Erdogan equation ( ]) a net crack growth rate can be defined. Equation (1). Con-stemts C and m are the Paris-Erdogan constants, and AK is the stress intensity factor for the crack. 

Figure 2. Validation of CL program of crack propagation in PE 100 material usin Paris-Erdogan equation [2]...

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