https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 05 Jun 2026 22:17:43 GMT 2026-06-05T22:17:43Z http://hdl.handle.net/10985/9719 Fiber type effect on tribological behavior when cutting natural fiber reinforced plastics MEZGHANI, Sabeur; EL MANSORI, Mohamed; CHEGDANI, Faissal Recently, natural fiber reinforced plastic (NFRP) materials are becoming a viable alternative to synthetic fiber in many industrial applications which not require high structural performances. However, machining of NFRP such as milling process is almost unavoidable operation to facilitate the parts assembly in addition to the finishing of final products. The present study thus focused on the influence of natural fiber types on tribological behavior during profile milling process. Three types of short natural fibers (bamboo, sisal and miscanthus) reinforced polypropylene (PP) composites are investigated. The quality of NFRP machined surface is quantified using a multiscale analysis based on wavelets decomposition. The natural fiber effect related to the machined surface quality is hence identified at all scales from roughness to waviness. The bamboo fibers reinforced plastics which exhibit high contact stiffness shows the smoother surface finish after machining. Therefore, the multiscale surface roughness is used as descriptor of natural fiber influence on the machining mechanisms and to establish the cutting signature of NFRP materials. The authors acknowledge the urban community of Châlonsen Champagne(Cités en Champagne) for their financial support. The authors also wish to thank “AD majoris SAS France” for providing the NFRP samples used in this research. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9719 2015-01-01T00:00:00Z MEZGHANI, Sabeur EL MANSORI, Mohamed CHEGDANI, Faissal Recently, natural fiber reinforced plastic (NFRP) materials are becoming a viable alternative to synthetic fiber in many industrial applications which not require high structural performances. However, machining of NFRP such as milling process is almost unavoidable operation to facilitate the parts assembly in addition to the finishing of final products. The present study thus focused on the influence of natural fiber types on tribological behavior during profile milling process. Three types of short natural fibers (bamboo, sisal and miscanthus) reinforced polypropylene (PP) composites are investigated. The quality of NFRP machined surface is quantified using a multiscale analysis based on wavelets decomposition. The natural fiber effect related to the machined surface quality is hence identified at all scales from roughness to waviness. The bamboo fibers reinforced plastics which exhibit high contact stiffness shows the smoother surface finish after machining. Therefore, the multiscale surface roughness is used as descriptor of natural fiber influence on the machining mechanisms and to establish the cutting signature of NFRP materials. http://hdl.handle.net/10985/17488 Thermal Effects on Tribological Behavior in Machining Natural Fiber Composites TAKABI, Behrouz; TAI, Bruce; BUKKAPATNAM, Satish; EL MANSORI, Mohamed; CHEGDANI, Faissal Machining natural fibers reinforced plastic (NFRP) composites is nowadays a real challenge for academia and industries. These eco-friendly materials are emerging in automotive and aeronautical industries thanks to many benefits for sustainable development. It is then necessary to anticipate their machining processes for integrating them into the NFRP industrial production chains. This paper investigates the thermal effect on the machinability of unidirectional flax fibers reinforced polypropylene composites (UDF/PP) regarding to the cutting contact geometry. For this aim, orthogonal cutting process has been performed on UDF/PP composites at room and low temperature of composite samples. Cutting contact geometry has been explored by changing the tool rake angle. Results show that reducing the cutting temperature affects the chip morphology and improves the cutting behavior of flax fibers which ameliorates the machinability of UDF/PP composites. This machinability is also improved by cutting with a smaller positive rake angle that increases the cutting contact stiffness with flax fibers. This study allows determining a new relevant indicator parameter of NFRP machinability based on the cutting friction. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/17488 2018-01-01T00:00:00Z TAKABI, Behrouz TAI, Bruce BUKKAPATNAM, Satish EL MANSORI, Mohamed CHEGDANI, Faissal Machining natural fibers reinforced plastic (NFRP) composites is nowadays a real challenge for academia and industries. These eco-friendly materials are emerging in automotive and aeronautical industries thanks to many benefits for sustainable development. It is then necessary to anticipate their machining processes for integrating them into the NFRP industrial production chains. This paper investigates the thermal effect on the machinability of unidirectional flax fibers reinforced polypropylene composites (UDF/PP) regarding to the cutting contact geometry. For this aim, orthogonal cutting process has been performed on UDF/PP composites at room and low temperature of composite samples. Cutting contact geometry has been explored by changing the tool rake angle. Results show that reducing the cutting temperature affects the chip morphology and improves the cutting behavior of flax fibers which ameliorates the machinability of UDF/PP composites. This machinability is also improved by cutting with a smaller positive rake angle that increases the cutting contact stiffness with flax fibers. This study allows determining a new relevant indicator parameter of NFRP machinability based on the cutting friction. http://hdl.handle.net/10985/15175 Experimental study of coated tools effects in dry cutting of natural fiber reinforced plastics MEZGHANI, Sabeur; EL MANSORI, Mohamed; CHEGDANI, Faissal This work aims to investigate the tribological effects of coated tools on the surface finish of natural fiber reinforced plastics (NFRPs) during profile milling process with particular emphasis on the natural fiber cutting mechanisms and tool wear. Both up-milling and down-milling configurations were considered. The cutting experiments were carried out on unidirectional flax fibers reinforced polypropylene resin (UDF/PP) using three different cutting tools. Uncoated tungsten carbide, titanium diboride (TiB2) coated and diamond coated were used to conduct profile milling tests. Tribological cutting contacts were evaluated by measuring the specific cutting energy. Surface state was acquired by a scanning electronic microscope (SEM) and an optical microscope (OM). Surface topography was measured using a 2D Surfascan stylus profilometer. Machined NFRP surface finish was characterized using standard and multiscale analysis based on wavelets transform. Results show that the cutting edge radius made by tool coating has a significant effect on surface finish. Natural fiber shearing is more efficient once the removed chip thickness exceeds the cutting edge radius value. Moreover, it had been demonstrated that the pertinent scales for surface finish analysis are between 50 μm and 1 mm which correspond to the multiscale fiber reinforcement structure. Furthermore, and unlike the uncoated tool, TiB2 and diamond coatings allow a good wear resistance of the cutting tools against the tribological solicitations of flax composite machining. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/15175 2015-01-01T00:00:00Z MEZGHANI, Sabeur EL MANSORI, Mohamed CHEGDANI, Faissal This work aims to investigate the tribological effects of coated tools on the surface finish of natural fiber reinforced plastics (NFRPs) during profile milling process with particular emphasis on the natural fiber cutting mechanisms and tool wear. Both up-milling and down-milling configurations were considered. The cutting experiments were carried out on unidirectional flax fibers reinforced polypropylene resin (UDF/PP) using three different cutting tools. Uncoated tungsten carbide, titanium diboride (TiB2) coated and diamond coated were used to conduct profile milling tests. Tribological cutting contacts were evaluated by measuring the specific cutting energy. Surface state was acquired by a scanning electronic microscope (SEM) and an optical microscope (OM). Surface topography was measured using a 2D Surfascan stylus profilometer. Machined NFRP surface finish was characterized using standard and multiscale analysis based on wavelets transform. Results show that the cutting edge radius made by tool coating has a significant effect on surface finish. Natural fiber shearing is more efficient once the removed chip thickness exceeds the cutting edge radius value. Moreover, it had been demonstrated that the pertinent scales for surface finish analysis are between 50 μm and 1 mm which correspond to the multiscale fiber reinforcement structure. Furthermore, and unlike the uncoated tool, TiB2 and diamond coatings allow a good wear resistance of the cutting tools against the tribological solicitations of flax composite machining. http://hdl.handle.net/10985/15195 On the multiscale tribological signatures of the tool helix angle in profile milling of woven flax fiber composites MEZGHANI, Sabeur; EL MANSORI, Mohamed; CHEGDANI, Faissal The present study is focused on tribological and multiscale analysis for the machined surfaces of bi-directional flax fibers reinforced polypropylene composites. This is to track the multiscale effect of the helix angle of the cutting tool, related to its kinematic, on the cutting mechanisms. The results show that the helix angle has significant effect on the tribological performances which affect the tribo-contact interaction between the flax fibers and the cutting edge. The fibers orientation in the woven reinforcement has significant effect on the surface quality. The multiscale analysis reveals the pertinent scales that activate the helix angle effect. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/15195 2016-01-01T00:00:00Z MEZGHANI, Sabeur EL MANSORI, Mohamed CHEGDANI, Faissal The present study is focused on tribological and multiscale analysis for the machined surfaces of bi-directional flax fibers reinforced polypropylene composites. This is to track the multiscale effect of the helix angle of the cutting tool, related to its kinematic, on the cutting mechanisms. The results show that the helix angle has significant effect on the tribological performances which affect the tribo-contact interaction between the flax fibers and the cutting edge. The fibers orientation in the woven reinforcement has significant effect on the surface quality. The multiscale analysis reveals the pertinent scales that activate the helix angle effect. http://hdl.handle.net/10985/15196 Multiscale tribo-mechanical analysis of natural fiber composites for manufacturing applications WANG, Zimo; BUKKAPATNAM, Satish; EL MANSORI, Mohamed; CHEGDANI, Faissal This paper aims to investigate the tribo-mechanical behavior of natural fiber reinforced plastic (NFRP) composites with specific consideration of the multiscale complex structure of natural fibers. Understanding the multiscale tribo-mechanical performances of these eco-friendly materials can lead to a better design of their manufacturing processes. Nanoindentation and nanoscratching experiments are conducted on flax fibers reinforced polypropylene composites using a triboindenter at a specific contact scale generated by the tip indenter radius (100 nm). Results confirm the significant effect of the geometric contact scale on the flax fibers stiffness. Moreover, flax fibers friction shows a multiscale behavior where the mechanisms of nano-friction are vastly different from those of micro-friction, which is related to the physical phenomena arisen at each scale. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/15196 2018-01-01T00:00:00Z WANG, Zimo BUKKAPATNAM, Satish EL MANSORI, Mohamed CHEGDANI, Faissal This paper aims to investigate the tribo-mechanical behavior of natural fiber reinforced plastic (NFRP) composites with specific consideration of the multiscale complex structure of natural fibers. Understanding the multiscale tribo-mechanical performances of these eco-friendly materials can lead to a better design of their manufacturing processes. Nanoindentation and nanoscratching experiments are conducted on flax fibers reinforced polypropylene composites using a triboindenter at a specific contact scale generated by the tip indenter radius (100 nm). Results confirm the significant effect of the geometric contact scale on the flax fibers stiffness. Moreover, flax fibers friction shows a multiscale behavior where the mechanisms of nano-friction are vastly different from those of micro-friction, which is related to the physical phenomena arisen at each scale. http://hdl.handle.net/10985/17487 Thermo-mechanical Effects in Mechanical Polishing of Natural Fiber Composites BUKKAPATNAM, Satish; EL MANSORI, Mohamed; CHEGDANI, Faissal Efficient machining and finishing of natural fiber reinforced plastic (NFRP) composites is essential for realizing the industrial application envisaged of these promising, environmentally friendly materials. While prior efforts allude to the multiscale nature of their material removal mechanisms, little understanding currently exists on the thermal effects of their material removal behaviors. This experimental study aims to characterize the thermal effects during the polishing of NFRP composites. For this aim, dry and wet polishing have been performed following several polishing steps on unidirectional flax fibers reinforced polypropylene composites. Results from scanning electron microscopy (SEM) and optical interferometry studies reveal a significant difference between dry and wet polishing in terms of surface artifacts induced. This difference is enhanced at higher sliding speed, indicating that the asperity removal during polishing is mostly thermally mediated. The results also indicate that the surface forming of flax fibers is related to the mechanical contact scale engendered by the grit size. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/17487 2018-01-01T00:00:00Z BUKKAPATNAM, Satish EL MANSORI, Mohamed CHEGDANI, Faissal Efficient machining and finishing of natural fiber reinforced plastic (NFRP) composites is essential for realizing the industrial application envisaged of these promising, environmentally friendly materials. While prior efforts allude to the multiscale nature of their material removal mechanisms, little understanding currently exists on the thermal effects of their material removal behaviors. This experimental study aims to characterize the thermal effects during the polishing of NFRP composites. For this aim, dry and wet polishing have been performed following several polishing steps on unidirectional flax fibers reinforced polypropylene composites. Results from scanning electron microscopy (SEM) and optical interferometry studies reveal a significant difference between dry and wet polishing in terms of surface artifacts induced. This difference is enhanced at higher sliding speed, indicating that the asperity removal during polishing is mostly thermally mediated. The results also indicate that the surface forming of flax fibers is related to the mechanical contact scale engendered by the grit size. http://hdl.handle.net/10985/17518 New Multiscale Approach for Machining Analysis of Natural Fiber Reinforced Bio-Composites EL MANSORI, Mohamed; CHEGDANI, Faissal Natural fibers are emerging in many industrial sectors to perform eco-friendly materials such as bio-composites. However, machining of natural fiber reinforced polymer (NFRP) composites remains a complex manufacturing process and the machinability of industrial components underlies a specific approach that involves the multiscale structure of natural fibers. This paper presents first a multiscale method used in machinability rating of NFRP. The fundamentals of the multiscale method are hence applied to experimentally assess the machinability of a complete industrial bio-composite part. Results show that machining NFRP composites requires specific analysis scales that are intimately linked to the natural fibrous structure. The multiscale method can be used to improve the experimental design of NFRP machining and, above all, to determine the optimum process parameters that reflect the multiscale machining characteristics of these bio-based materials. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/17518 2019-01-01T00:00:00Z EL MANSORI, Mohamed CHEGDANI, Faissal Natural fibers are emerging in many industrial sectors to perform eco-friendly materials such as bio-composites. However, machining of natural fiber reinforced polymer (NFRP) composites remains a complex manufacturing process and the machinability of industrial components underlies a specific approach that involves the multiscale structure of natural fibers. This paper presents first a multiscale method used in machinability rating of NFRP. The fundamentals of the multiscale method are hence applied to experimentally assess the machinability of a complete industrial bio-composite part. Results show that machining NFRP composites requires specific analysis scales that are intimately linked to the natural fibrous structure. The multiscale method can be used to improve the experimental design of NFRP machining and, above all, to determine the optimum process parameters that reflect the multiscale machining characteristics of these bio-based materials. http://hdl.handle.net/10985/15176 Correlation between mechanical scales and analysis scales of topographic signals under milling process of natural fibre composites MEZGHANI, Sabeur; EL MANSORI, Mohamed; CHEGDANI, Faissal This article aims to find the relation between the multiscale mechanical structure of natural fibre reinforced plastic composites and the analysis scales in the topographic signals of machined surfaces as induced by profile milling process. Bamboo, sisal and miscanthus fibres reinforced polypropylene composites were considered in this study. The multiscale process signature of natural fibre reinforced plastic machined surfaces based on wavelet decomposition was determined. Then, the impact of wavelet function was inspected by testing different wavelet shapes. Finally, the analysis of variance was carried out to exhibit the contribution rate of fibre stiffness and tool feed on the machined surface roughness at each analysis scale. Results demonstrate that studying the machining of natural fibre reinforced plastic requires the selection of the relevant scales. They show also the insignificance of the wavelet choice. This study proves that the contribution rate of fibre stiffness and tool feed on machined surface roughness is significantly dependent on the analysis scales, which are directly related to the mechanical properties of natural fibres structure inside the composite. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/15176 2017-01-01T00:00:00Z MEZGHANI, Sabeur EL MANSORI, Mohamed CHEGDANI, Faissal This article aims to find the relation between the multiscale mechanical structure of natural fibre reinforced plastic composites and the analysis scales in the topographic signals of machined surfaces as induced by profile milling process. Bamboo, sisal and miscanthus fibres reinforced polypropylene composites were considered in this study. The multiscale process signature of natural fibre reinforced plastic machined surfaces based on wavelet decomposition was determined. Then, the impact of wavelet function was inspected by testing different wavelet shapes. Finally, the analysis of variance was carried out to exhibit the contribution rate of fibre stiffness and tool feed on the machined surface roughness at each analysis scale. Results demonstrate that studying the machining of natural fibre reinforced plastic requires the selection of the relevant scales. They show also the insignificance of the wavelet choice. This study proves that the contribution rate of fibre stiffness and tool feed on machined surface roughness is significantly dependent on the analysis scales, which are directly related to the mechanical properties of natural fibres structure inside the composite. http://hdl.handle.net/10985/15177 Scale effect on tribo-mechanical behavior of vegetal fibers in reinforced bio-composite materials MEZGHANI, Sabeur; EL MANSORI, Mohamed; CHEGDANI, Faissal; MONTAGNE, Alex The nature of friction of vegetal fiber and polymeric matrix in bio-composite materials is very important for many industrial applications. In order to design natural fiber composites for structural applications, the scientific understanding of tribo-mechanical phenomena inside the heterogeneous structure of natural fibers and also the overall heterogeneous structure of the bio-composite is required. This implies a special focus on the fundamental aspects of vegetal fiber friction at the macro-, meso-, and microscale. This research paper investigates the multiscale mechanical and friction properties of natural fibers. The mechanical properties of flax fibers, glass fibers (as a reference) and polypropylene matrix has been evaluated at microscale and mesoscale by Atomic Force Microscopy (AFM) and Nanoindenter XP (MTS Nano Instruments), respectively, using nanoindentation technique. At the macroscale, the mechanical behavior has been considered for the global composite structure. The micro-friction response of each composite component has been measured by instrumenting AFM for scratch test technique. The results show the scale dependence of mechanical behavior for flax fibers, unlike glass fibers and polypropylene matrix where their mechanical performances are independent of the analysis scale. Tribological results in terms of dynamic friction coefficient show that flax fibers induce more friction than glass fibers, while polypropylene matrix generates the highest friction. This is sign that vegetal fiber friction is scale dependent property as shown when referring to the contact mechanics theory. The arisen results are very important for many technical applications in PMCs surface engineering based on plant fibers. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/15177 2017-01-01T00:00:00Z MEZGHANI, Sabeur EL MANSORI, Mohamed CHEGDANI, Faissal MONTAGNE, Alex The nature of friction of vegetal fiber and polymeric matrix in bio-composite materials is very important for many industrial applications. In order to design natural fiber composites for structural applications, the scientific understanding of tribo-mechanical phenomena inside the heterogeneous structure of natural fibers and also the overall heterogeneous structure of the bio-composite is required. This implies a special focus on the fundamental aspects of vegetal fiber friction at the macro-, meso-, and microscale. This research paper investigates the multiscale mechanical and friction properties of natural fibers. The mechanical properties of flax fibers, glass fibers (as a reference) and polypropylene matrix has been evaluated at microscale and mesoscale by Atomic Force Microscopy (AFM) and Nanoindenter XP (MTS Nano Instruments), respectively, using nanoindentation technique. At the macroscale, the mechanical behavior has been considered for the global composite structure. The micro-friction response of each composite component has been measured by instrumenting AFM for scratch test technique. The results show the scale dependence of mechanical behavior for flax fibers, unlike glass fibers and polypropylene matrix where their mechanical performances are independent of the analysis scale. Tribological results in terms of dynamic friction coefficient show that flax fibers induce more friction than glass fibers, while polypropylene matrix generates the highest friction. This is sign that vegetal fiber friction is scale dependent property as shown when referring to the contact mechanics theory. The arisen results are very important for many technical applications in PMCs surface engineering based on plant fibers. http://hdl.handle.net/10985/15197 Friction scale effect in drilling natural fiber composites EL MANSORI, Mohamed; CHEGDANI, Faissal This work aims to investigate the multiscale tribological behavior when drilling natural fiber composites by changing the tool-composite interface trough the modification of the tool coating. Drilling experiments were carried out on bidirectional flax fibers reinforced polypropylene resin using the same drilling tool geometry with three different coating properties. Results show that the tribo-mechanical behavior of the drilling operation is affected by changing the tool coating at different scale levels. This multiscale behavior is related to the intrinsic friction properties of each coating nature that influence the tribo-contact at the interface between the cutting tool edge and the composite surface. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10985/15197 2018-01-01T00:00:00Z EL MANSORI, Mohamed CHEGDANI, Faissal This work aims to investigate the multiscale tribological behavior when drilling natural fiber composites by changing the tool-composite interface trough the modification of the tool coating. Drilling experiments were carried out on bidirectional flax fibers reinforced polypropylene resin using the same drilling tool geometry with three different coating properties. Results show that the tribo-mechanical behavior of the drilling operation is affected by changing the tool coating at different scale levels. This multiscale behavior is related to the intrinsic friction properties of each coating nature that influence the tribo-contact at the interface between the cutting tool edge and the composite surface.