Analyse thermomécanique des lois de comportement par thermographie infrarouge

Abstract

Résumé. - Abstract. -The knowledge of dissipative and non dissipative phenomena associated to quasi-static déformation processes, is a fundamental supplementary asset for determination of thermomechanical behaviour law. On depicts, in this paper, an experimental set-up, using infra-red technics, which allows to observe thermal and energetical phenomena during sample déformation. After restating the definition of the energy balance, in case of elastic-plastic materials, the relationship between the dissipation (or the stored energy of cold working) and the hardening state variables are recalled. The dissipation is continuously evaluated during monotonic tensile test. Numerized maps of surface temperature are used. The experimental arrangement is described ; then the physical model, which allows to relate the dissipation to the temperature signals, and the calibration method are successively introduced. Results on several materials are shown and their incidence on the behaviour law is succinctly mentioned.Revue Phys. Appl. 24 (1989) 215-225 FÉVRIER 1989, Classification Physics Abstracts

Mechanisms of deformation in crystallizable natural rubber. Part 2: Quantitative calorimetric analysis

“…The 2D equation (2) can be reduced to a "0D" formulation in the case of heat source fields which are homogeneous in the specimen [21]. In the present study, this approach is relevant because the tests are assumed to be homogeneous in terms of strain and stress.…”

Monotone strain-stress models for shape memory alloys hysteresis loop and pseudoelastic behaviorx

“…Indeed, the symmetry of the problem (see section 4, but also [4] and [8]) implies that W ch and respectively W m are respectively approximately equal to the caloric energy t t0 V0…”

POD Preprocessing of IR Thermal Data to Assess Heat Source Distributions

“…At this time, because of the slowness of the first digitization systems of mono-detector cameras used in the 1990s (typically two digitized images per second), spectral solutions (SPS) of the heat equation were used to estimate heat sources [8]. The main advantages of the spectral method is the knowledge of the eigen-functions of the Laplacian operator -typically sine and cosine functions for parallelepipedic specimens -which allows assessment of the conduction heat losses without markedly amplifying the noise (use of truncated solutions to limit noise effects).…”

“…That is why other methods have been proposed. In the past, truncated spectral solutions (SPS) of the heat equation were used [8] as well as local least-squares (LSQ) analytical approximations [5].…”