PALIN-LUC, Thierry LASSERRE, Serge BERARD, J-Y.
Fatigue tests were performed on a spheroidal graphite cast iron in four point plane bending under constant stress amplitude and block loading conditions. The microstructure of this material has a ‘bull’s eyes’ appearance, i.e. the spheroids of graphite are surrounded by ferrite and these nodules and ferrite zones are included in a pearlitic matrix....
PALIN-LUC, Thierry SELLIER, E. D'ERRICO, F. VANHAEREN, M.
The replica technique is often used to study damage evolution at the surface of specimens or industrial components and understand the physicial phenomena responsible for fatigue crack initiation before failure. Replicas are usually made from acetate cellulose film. This paper presents an alternative technique generally used by archaeologists to stu...
INAL, Karim BERVEILLER, Marcel LEBRUN, Jean-Lou PESCI, Raphaël
The behavior and the fracture mechanisms of the 16MND5 bainitic pressure vessel steel are studied using a local approach of fracture on a crystallographic scale. A series of tensile tests are performed on the material at various temperatures ranging from - 96°C to -60°C: the damage is observed with a Scanning Electron Microscope (SEM) while the res...
PALIN-LUC, Thierry MOREL, Franck
The stress gradient effect on the fatigue limit is an important factor which has to be taken into account for an efficient transfer of fatigue data from laboratory tests to design of industrial components. A short review of some multiaxial high cycle fatigue criteria considering this effect is presented. On the basis of the two local mesoscopic app...
COSTES, Jean-Philippe DECES-PETIT, Cyrille ALTINTAS, Yusuf KO, Pak
This paper presents a model of load distribution on the cutting edge of a tool during machining Medium Density Fibreboard (MDF). A series of cutting tests has been carried out with tools having designated rake face contact lengths. Utilising the experimental data and a mechanics approach developed earlier by the third author, a model to estimate th...
BIGERELLE, Maxence IOST, Alain
This paper comments upon some statistical aspects of the slit island method which is widely used to calculate the fractal dimension of fractured surfaces or of materials’ features like grain geometry. If a noise is introduced when measuring areas and perimeters of the islands (experimental errors), it is shown that errors are made in the calculatio...
MALHERBE, S BENAYOUN, Stéphane MOREL, Anne IOST, Alain
Dans cet article, nous présentons une expression de la courbe d'indentation instrumentée d'un matériau élastoplastique pouvant s'écrouir. Cette expression nécessite d'expliciter la pression moyenne de contact entre l'indenteur et le matériau, ainsi que de tenir compte de la forme que prend la surface du matériau sous l'indenteur. Le cas d'un indent...
PALIN-LUC, Thierry MOREL, Franck
This paper aims to propose a new interpretation of several energy based critical plane high cycle fatigue criteria. More exactly, the meaning of several global energy based criteria is detailed from the calculation of normal and shear work on a critical plane. This study is limited to multiaxial fatigue under constant amplitude and synchronous load...
BIGERELLE, Maxence NAJJAR, Denis IOST, Alain
In this paper, we propose to create a fractal function defined by an infinite series to model worn surfaces obtained by a grinding process. In this series, each elementary term characterizes a wear process at a given scale. This series is only defined by two parameters: an amplitude parameter and the fractal dimension. This model is tested on worn ...
IOST, Alain RUDERMAN, Y. BIGERELLE, Maxence
La caractérisation des propriétés mécaniques des revêtements, et plus particulièrement de leur dureté est d'une grande importance dans le milieu industriel et fait l'objet de nombreuses études. Le plus souvent, la mesure directe de cette grandeur n'est pas possible, puisque sa valeur est influencée par les caractéristiques du substrat sur lequel le...