A mesoscopic approach to describe the high cycle fatigue behaviour of metals submitted to multiaxial loading.

• Autorzy: Morel F.
• Konferencja: IV Letnia Szkoła organizowana w powiązaniuz programem TEMPUS PHARE S-JEP-11033/96. Mechanika pękania z uwzględnieniem wpływu środowiska korozyjnego. Obciążenia wieloosiowe.
• Języki publikacji: EN

Abstrakty

EN

A general theory of fatigue has been presented in this work. This theory is based on a mesoscopic approach. The macroscopic behaviour of a metallic component is purely elastic in the high cycle fatigue regime. However, within an elementary material volume V, some plastically less resistance grains exist, that suffer plastic glide. The plastic behaviour of such gliding crystals under cyclic loading has been investigated. OROWAN was the first in the late thirties to propose a unidimensional fatigue model based on an evaluation of the local stress. Later, to generalize this theory, two scales of material description have been introduced: the macroscopic scale and the mesoscopic scale. The local stresses and strains, acting at the level of the grains of a metallic aggregate, was then linked to the usual macroscopic quantities, through the LIN-TAYLOR assumption. It was shown that the fatigue limit could be related to the possibility of some plastically deforming grains to reach an elastic shakedown state. Both the unlimited (fatigue criterion) as well as the limited (Wöhler curve) fatigue life regimes can be covered with this theory. The most efficient criteria are expressed by the restraint applied on the plastic strain accumulated by a cycling loading in the plastically flowing grains of the metallic aggregate. Besides, a new fatigue prediction method has been proposed with the accumulated plastic mesostrain as the damage variable. As a general conclusion, it can be observed that the mesoscopic approach provides a sound physical basis to investigate the fatigue problem.

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Prace Naukowe Instytutu Materiałoznawstwa i Mechaniki Technicznej Politechniki Wrocławskiej. Konferencje
• Rocznik: 1998
• Tom: Vol. 60, nr 8
• Strony: 12--54
• Opis fizyczny: Bibliogr. 17 poz.,tab. 1, rys. 24, załąc

Twórcy

autor

Morel F.

• Laboratoire de Mecanique et de Physique des Materiaux (LMPM) - URA CNRS 863 ENSMA - Site du Futuroscope - BP 109 , 86960 FUTUROSCOPE cedex FRANCE Tel. [phone] fax: [phone],