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Uniaxial static traction tests and fatigue tests, performed on smooth and notched specimens of C40
steel have confirmed that starting from the thermal analysis of the specimen under test it is possible to evaluate
the fatigue limit of the material.
Further, starting from post processing image analysis, the parameters that characterize the dynamic behavior of
the material have been characterized; in particular in the case of notched specimen.
Test results have shown that utilizing adequate sensors it is possible to make estimations very close to the real
values of both the stress concentration factor and the fatigue-stress concentration factor. It is possible therefore
to distinguish between the total elastic behavior and the partial elastic behavior that is the behavior
characterized by some irreversible deformation of specific microarea of the material.
The experimental results proposed in the present paper, have outlined the possibility to define some parameters
related to the total deformation density energy. Those parameters can be determined also in the cases of local
plasticization that usually does not allow to provide immediate and verified measurements.