A hybrid model for modelling arbitrary cracks in isotropic plate structures

Damage modelling is essential in preliminary structural design and non-destructive damage detection. This paper investigates changes in natural frequencies of plates due to an arbitrarily aligned crack. A novel hybrid method couples an exact strip model for the intact part with a finite element model for the cracked part. The crack is modelled as a rotational spring with additional rotational freedoms being added to the finite element nodes. The method is validated against published results for through-the-depth cracks. Cracks with varying direction, location, depth and length are used to study the effects of changing the crack parameters.