https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sat, 07 Mar 2026 00:21:06 GMT 2026-03-07T00:21:06Z http://hdl.handle.net/10985/14135 Influence of toolpath and clamping strategies on stainless steel plates distorsion after machining CHARRONDIERE, Guillaume; CHERIF, Iheb; POULACHON, Gerard; COTTON, Dominique; MARTINS DO OUTEIRO, Jose Carlos Heat exchangers in nuclear power generation plants are made of thin stainless-steel plates assembled together in order to improve their efficiency and compactness. To ensure the assembly, the global distortion of those plates must be mastered and minimized, mainly by predicting the evolution of the residual stress field during their manufacturing process chain. The residual stresses generated during rolling are removed by heat treatments process that also induce another stress field while cooling. During machining, those residual stresses are redistributed to reach another equilibrium state, leading to a macroscopic part distortion. The objective of this work is to study the influence of the machining toolpath and clamping strategies on the global part distortion so as to optimize the manufacturing process chain. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/14135 2018-01-01T00:00:00Z CHARRONDIERE, Guillaume CHERIF, Iheb POULACHON, Gerard COTTON, Dominique MARTINS DO OUTEIRO, Jose Carlos Heat exchangers in nuclear power generation plants are made of thin stainless-steel plates assembled together in order to improve their efficiency and compactness. To ensure the assembly, the global distortion of those plates must be mastered and minimized, mainly by predicting the evolution of the residual stress field during their manufacturing process chain. The residual stresses generated during rolling are removed by heat treatments process that also induce another stress field while cooling. During machining, those residual stresses are redistributed to reach another equilibrium state, leading to a macroscopic part distortion. The objective of this work is to study the influence of the machining toolpath and clamping strategies on the global part distortion so as to optimize the manufacturing process chain. http://hdl.handle.net/10985/14136 Impact des contraintes résiduelles sur la déformation en usinage de plaques en 316L CHERIF, Iheb; COTTON, Dominique; MARTINS DO OUTEIRO, Jose Carlos; POULACHON, Gerard La fabrication des plaques en 316L de grandes tailles et de faibles épaisseurs destinées aux échangeurs thermiques passe par plusieurs étapes de fabrication (laminage, traitement thermique et finalement l’usinage), afin au final de les assembler. Durant ce processus, des contraintes résiduelles seront générées, redistribuées et relaxées. En conséquence, des déformations plus ou moins importantes seront engendrées à chaque étape de la gamme de fabrication. Ce qui implique l’apparition d’erreurs dimensionnelles et de forme impactant leur planéité. D’abord, une simulation numérique des étapes de pré-usinage a été effectuée pour analyser la distribution des contraintes résiduelles internes. Pour ce faire, les données d’entrée manquantes doivent être déterminées, ainsi que les valeurs des coefficients d'échange thermique (avec l'eau et l'air) et de l'émissivité (avec l'air). La méthode inverse couplée à des algorithmes d’optimisation a été utilisée pour définir les paramètres manquants au modèle numérique. Ensuite, la mesure de la répartition des contraintes résiduelles à travers l'épaisseur sera faite par la méthode d'enlèvement des couches pour la comparer avec les résultats de la simulation numérique. Afin de consolider la validité de la modélisation, des mesures par diffraction de neutrons ont été réalisées. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/14136 2018-01-01T00:00:00Z CHERIF, Iheb COTTON, Dominique MARTINS DO OUTEIRO, Jose Carlos POULACHON, Gerard La fabrication des plaques en 316L de grandes tailles et de faibles épaisseurs destinées aux échangeurs thermiques passe par plusieurs étapes de fabrication (laminage, traitement thermique et finalement l’usinage), afin au final de les assembler. Durant ce processus, des contraintes résiduelles seront générées, redistribuées et relaxées. En conséquence, des déformations plus ou moins importantes seront engendrées à chaque étape de la gamme de fabrication. Ce qui implique l’apparition d’erreurs dimensionnelles et de forme impactant leur planéité. D’abord, une simulation numérique des étapes de pré-usinage a été effectuée pour analyser la distribution des contraintes résiduelles internes. Pour ce faire, les données d’entrée manquantes doivent être déterminées, ainsi que les valeurs des coefficients d'échange thermique (avec l'eau et l'air) et de l'émissivité (avec l'air). La méthode inverse couplée à des algorithmes d’optimisation a été utilisée pour définir les paramètres manquants au modèle numérique. Ensuite, la mesure de la répartition des contraintes résiduelles à travers l'épaisseur sera faite par la méthode d'enlèvement des couches pour la comparer avec les résultats de la simulation numérique. Afin de consolider la validité de la modélisation, des mesures par diffraction de neutrons ont été réalisées. http://hdl.handle.net/10985/14019 Phenomenological study of chip flow/formation and unified cutting force modelling during Ti6Al4V alloy turning operations CHERIF, Iheb; DORLIN, Théo; MARCON, Bertrand; FROMENTIN, Guillaume; KARAOUNI, Habib Mechanistic approach for prediction of cutting forces are showing limits when it comes to enhance the cutting force modelling for specific applications of high-value added and thin parts, which are made of difficult-to-cut materials such as titanium alloys. This is the reason why precise cutting force modelling is needed in order to avoid deflection during machining. Therefore, this contribution aims to improve the description of the chip formation in cutting force modelling thanks to an original experimental set-up built up to observe in-situ the chip flow and measure the cutting forces during Ti6Al4V turning. This study highlights the fact that the chip flow direction has a significant effect on cutting forces and can be influenced by several parameters. In view of the results obtained, a generalised chip flow direction model is suggested. Chips morphology observation is also conducted with the purpose of providing experimental observations physical meaning. Afterwards, a cutting force model is proposed which takes into account the chip flow direction influence. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/14019 2018-01-01T00:00:00Z CHERIF, Iheb DORLIN, Théo MARCON, Bertrand FROMENTIN, Guillaume KARAOUNI, Habib Mechanistic approach for prediction of cutting forces are showing limits when it comes to enhance the cutting force modelling for specific applications of high-value added and thin parts, which are made of difficult-to-cut materials such as titanium alloys. This is the reason why precise cutting force modelling is needed in order to avoid deflection during machining. Therefore, this contribution aims to improve the description of the chip formation in cutting force modelling thanks to an original experimental set-up built up to observe in-situ the chip flow and measure the cutting forces during Ti6Al4V turning. This study highlights the fact that the chip flow direction has a significant effect on cutting forces and can be influenced by several parameters. In view of the results obtained, a generalised chip flow direction model is suggested. Chips morphology observation is also conducted with the purpose of providing experimental observations physical meaning. Afterwards, a cutting force model is proposed which takes into account the chip flow direction influence. http://hdl.handle.net/10985/17656 Instrumented clamping device and numerical simulations to study machining distortion CHERIF, Iheb; COTTON, Dominique; POULACHON, Gerard; MARTINS DO OUTEIRO, Jose Carlos; BROSSE, Alexandre; REBELO KORNMEIER, Joana Machining part distortion is due to residual stresses induced by previous manufacturing processes. This study aims to evaluate the influence of machining conditions on AISI 316L plate distortion. Therefore, a special experimental device with force sensors integrated in the clamping system and numerical model of distortion were developed. Residual stresses due to previous machining processes were measured using a layer removal method and neutron diffraction technique. Then, distributions of these residual stresses were integrated in a developed model of machining distortion, which considers the clamping and machining sequence effects after each stage of the toolpath. A comparison of the experimental and numerical results revealed that the finite element method can adequately predict machining distortion. The results also suggest that clamping and machining sequence can affect part distortion. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/17656 2019-01-01T00:00:00Z CHERIF, Iheb COTTON, Dominique POULACHON, Gerard MARTINS DO OUTEIRO, Jose Carlos BROSSE, Alexandre REBELO KORNMEIER, Joana Machining part distortion is due to residual stresses induced by previous manufacturing processes. This study aims to evaluate the influence of machining conditions on AISI 316L plate distortion. Therefore, a special experimental device with force sensors integrated in the clamping system and numerical model of distortion were developed. Residual stresses due to previous machining processes were measured using a layer removal method and neutron diffraction technique. Then, distributions of these residual stresses were integrated in a developed model of machining distortion, which considers the clamping and machining sequence effects after each stage of the toolpath. A comparison of the experimental and numerical results revealed that the finite element method can adequately predict machining distortion. The results also suggest that clamping and machining sequence can affect part distortion. http://hdl.handle.net/10985/15637 Effects of toolpath and clamping strategies in machining distortion of stainless-steel parts CHERIF, Iheb; MARTINS DO OUTEIRO, Jose Carlos; COTTON, Dominique; POULACHON, Gerard; CHARRONDIERE, Guillaume; BROSSE, Alexandre Heat exchangers in new nuclear power generation plants are made of thin AISI 316L stainless-steel plates stacked together in order to improve their efficiency and compactness. To ensure the assembly, the global distortion of those plates must be mastered and minimized, mainly by predicting the evolution of the residual stress field during their manufacturing process chain. During machining, those residual stresses are redistributed to reach another equilibrium state, leading to a macroscopic part distortion. The main objective of this work is to study experimentally the influence of the machining toolpath and clamping strategies on the global part distortion. Then, a part distortion model is developed in order to verify the clamping effect on the distortion. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/15637 2019-01-01T00:00:00Z CHERIF, Iheb MARTINS DO OUTEIRO, Jose Carlos COTTON, Dominique POULACHON, Gerard CHARRONDIERE, Guillaume BROSSE, Alexandre Heat exchangers in new nuclear power generation plants are made of thin AISI 316L stainless-steel plates stacked together in order to improve their efficiency and compactness. To ensure the assembly, the global distortion of those plates must be mastered and minimized, mainly by predicting the evolution of the residual stress field during their manufacturing process chain. During machining, those residual stresses are redistributed to reach another equilibrium state, leading to a macroscopic part distortion. The main objective of this work is to study experimentally the influence of the machining toolpath and clamping strategies on the global part distortion. Then, a part distortion model is developed in order to verify the clamping effect on the distortion.