Discontinuous Yield and Large Deformation Analysis on Rotating Disk Based on J2 Deformation Theory

Rotating discs are used widely as important structural elements in mechanical engineering. In order to obtain an optimal structural design, it is necessary to estimate the angular velocity and the stress distribution of a rotating disc in fully plastic state. So J2 deformation Theory is used for large deformation analysis of axisymmetric rotating disk. The bursting speed of rotating disk, the stress distribution at instability and analysis on the elastic-plastic interface of rotating disk are studies in detail.

Crack Growth and Instable Fracture of Rotating Disks

The fracture of rotating disks that have cracks and/or notches is predicted employing the crack instability criterion based on the J-integral R-curve approach characterizing a material resistance to fracture. The J-integrals of cracked rotating disks are calculated by an elastic-plastic finite element method taking account of the thickness effects. Spin tests were carried out on disks having fatigue cracks and/or notches and the crack extensions as well as the bursting speeds of the disk specimens were measured. It is shown that the predicted values of bursting speed are in good agreement with those obtained by the experiment.