r5.05.08 Modeling of cracked rotors by equivalent stiffness as a function of the angle of rotation

Summary:

This document describes a method for taking into account cracks in rotors modelled in 1D.

It is based on theoretical developments described in the notes [1] and [2] and published in [3], establishing, under certain assumptions, the equivalence between a non-linear 3D model with contact calculation and a beam model where the nonlinearity due to the crack is simulated by an equivalent stiffness concentrated between two beam elements and a tabulated non-linear function of the angle of the bending moment with respect to the crack. This method used, in tree line calculation code CADYRO, was extended and validated compared to the experiment on test bench EUROPE [4]. It is included in the operator DYNA_VIBRA of*Code_Aster*.

• 1. Introduction and purpose
• 2. Assumptions
• 3. Benchmarks and notations
• 4. Determination of the equivalent stiffness of the crack
  • 4.1. Equivalent crack model
  • 4.2. Deformation energy
• 5. Bibliography
• 6. Document version history