Theoretical analysis, infrared and structural investigations of energy dissipation in metals under cyclic loading

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThe infrared and structural investigations of energy dissipation processes in metals subjected to cyclic loading have given impetus to the development of a new thermodynamic model with the capability of describing the energy balance under plastic deformation. The model is based on the statistical description of the mesodefect ensemble evolution and its influence on the dissipation ability of the material. Constitutive equations have been formulated for plastic and structural strains, which allow us to describe the stored and dissipated parts of energy under plastic flow. Numerical results indicate that theoretical predictions are in good agreement with the experimentally observed temperature data.

Fatigue limit by thermal analysis of specimen surface in mono axial traction test

“…Meneghetti [30] defined a theoretical model in order to determine the specific heat loss per cycle by surface temperature measurements during fatigue tests. Plekhev et al [31] developed a thermodynamic internal variable model to analyze the plastic deformation localization in metals. The model allows to describe the stored and dissipated parts of energy under plastic flow.…”

“…In the literature there are many analytical and numerical models that link the damage with energy and thermal variation for fatigue loading [25][26][27][28][29][30][31][32][33][34][35][36] and for static tensile test [37,38] and the hypothesis concerning the plasticization model, internal heat and external transmission, can help to find qualitative solutions only. Following the above easy engineering model, using the similar conditions assumed for the thermo-elasticity theory (adiabatic phenomena are accepted even at moderate strain rates), following the thermoelastic phase, the temperature vs test time can be written as: and ȕ =0,9 (constant) even if it is known that the Tailor coefficient is not constant particularly in the first strain rates [42,43].…”

Investigation of mechanical properties of Armco-iron during fatigue test

“…The analysis of published studies suggests that the physical mechanisms underlying these effects are not understood yet. At present, there are several models of this phenomenon, such as the model proposed in (Naimark et al 2000;Plekhov et al 2007a;Plekhov et al 2007b).…”

The application of the fluxgate method for the investigation of fracture under very high cycle fatigue

“…The analysis of published studies suggests that the physical mechanisms underlying these effects have yet to be understood. At present, there are several models of this phenomenon, such as the model proposed in [7,8].…”