Connection Among the Parameters of the Manson-Coffin, the Basquin and the Paris-Erdogan Equations

The material quality, the deformation rate, the temperature and the stress state influence mechanical behaviour and properties of different materials. Due to this great variety of the influencing factors we do not have one general model describing the behaviour of materials; then again we have to use a great number of material constants in order to characterize the material properties. The exponents of the Manson-Coffin, the Basquin and the Paris-Erdogan laws were applied for the verification of the connection among the fatigue fracture types. Own measured values and test results that can be found in the literature were used for the illustration of the connections. “Fracture surface”-s can be determined for characterizing the behaviour of different steel and aluminium grades and their welded joints, under cyclic loading conditions. It can be concluded that “fracture surface”-s are suitable for describing the fracture behaviour and the conversion of different fracture parameters of different steels and aluminium alloys.