Experimental evaluation of plastic wake on growing fatigue cracks from the analysis of residual displacement fields

  1. J.M. Vasco-Olmo 1
  2. A. Camacho-Reyes 1
  3. F.A. Díaz 1
  4. F.A. Antunes 2
  5. M.N. James 3
  1. 1 Departamento de Ingeniería Mecánica y Minera, Universidad de Jaén
  2. 2 Department of Mechanical Engineering, University of Coimbra
  3. 3 School of Marine Science & Engineering, University of Plymouth
Revue:
Revista española de mecánica de la fractura

ISSN: 2792-4246

Année de publication: 2022

Número: 3

Pages: 3-8

Type: Article

D'autres publications dans: Revista española de mecánica de la fractura

Résumé

A growing fatigue crack gives rise to a wake of material that has previously deformed plastically. In this work the plastic wake generated during fatigue crack growth is experimentally quantified by analysing the crack tip displacement fields measured with digital image correlation. A novel methodology based on applying a yield criterion is proposed by using the undamaged state of the specimen as a reference state in the image processing. The plastic wake was quantified from the differentiation of the residual displacement fields obtained for a load level as close to zero as possible in order to avoid any rigid body motion. The plastic wake extent was found by assuming that the boundary between the elastic and plastic regions would occur when the equivalent stress was higher than the yield stress of the material. The results presented can contribute to a better understanding of the mechanisms driving fatigue crack propagation.