Field theory of deformation and fracture applied to fatigue fracture

Le résumé fourni par la source

The physical process that underlies the transition from fatigue deformation to fatigue fracture is considered based on the concept of a recent comprehensive theory of deformation and fracture. A typical low-frequency cyclic loading test has been conducted for a thin aluminum plate specimen with the use of an optical interferometric technique to monitor the two-dimensional profile of the displacement field. A numerical model has been constructed to solve the governing equation derived from the field theory. Numerical analyses have been made under various scenarios to assimilate the spatiotemporal behaviors to the corresponding experimental results. This study has found (a) the loss of Poisson's effect along a boundary of specimen initiates the transition to fracture, (b) reduction in the shear modulus accelerates the transition process leading to temporal instability of the displacement field. This temporal instability causes the displacement to grow with time at some location of the specimen. This mechanism may be the direct cause of the generation of material discontinuity, which leads to a macroscopic crack.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.