12 Multi-mode Model and Calculation Method for Fatigue Damage …
159
Fig. 12.1 Bimodal fatigue curve
the suggestion of the proposed model of damage development based on the scheme
described above.
In order to match the model with the well-known criteria for multiaxial fatigue
failure, a stress-based criterion has been selected that describes the fatigue failure
associated with the normal crack microcracks development. This is a modification
of the Smith–Watson–Topper (SWT) criterion [4] described in [35], in which the
amplitudes of maximum tensile stresses play a decisive role in the development of
fatigue damage.
This chapter is organized as follows: Sect. 12.2 presents kinetic equations for
two fatigue modes and a condition to switch between them. Algorithm for fatigue
damage development calculation is presented in Sect. 12.3. Section 12.4 is dedicated
to calculation results both in LCF-HCF and VHCF modes. Section 12.5 concludes
the chapter.
12.2 Kinetic Equation for Damage
In this work, two different modes of fatigue loading are studied: classic LCF-HCF
mode and VHCF mode in Sects. 12.2.1 and 12.2.2, respectively. Also, an algorithm
to choose between them is presented in Sect. 12.2.3.
159
Fig. 12.1 Bimodal fatigue curve
the suggestion of the proposed model of damage development based on the scheme
described above.
In order to match the model with the well-known criteria for multiaxial fatigue
failure, a stress-based criterion has been selected that describes the fatigue failure
associated with the normal crack microcracks development. This is a modification
of the Smith–Watson–Topper (SWT) criterion [4] described in [35], in which the
amplitudes of maximum tensile stresses play a decisive role in the development of
fatigue damage.
This chapter is organized as follows: Sect. 12.2 presents kinetic equations for
two fatigue modes and a condition to switch between them. Algorithm for fatigue
damage development calculation is presented in Sect. 12.3. Section 12.4 is dedicated
to calculation results both in LCF-HCF and VHCF modes. Section 12.5 concludes
the chapter.
12.2 Kinetic Equation for Damage
In this work, two different modes of fatigue loading are studied: classic LCF-HCF
mode and VHCF mode in Sects. 12.2.1 and 12.2.2, respectively. Also, an algorithm
to choose between them is presented in Sect. 12.2.3.