Benoit Cosson

IMT Lille Douai · Polymer and Composite Technology & Mechanical Engineering (TPCIM)

The present study investigated the influence of temperature on molecular interdiffusion at the interface during the laser transmission welding of 3D-printed continuous carbon-fiber-reinforced thermoplastic composites. In order to accurately measure the temperature at the weld interface, a series of thermocouples were embedded in the laser-absorbent...

The determination of the laser intensity profile necessary to weld two thermoplastic parts is crucial for understanding and optimizing the laser welding process in polymers and composite materials. Traditional methods of measuring the laser beam intensity profile, such as laser beam profiling techniques, can be difficult to implement and expensive....

Laser transmission welding (LTW) is a suitable process for assembling thermoplastic materials. This joining process is used to assemble most thermoplastics, but high-performance thermoplastics, such as polyetherketoneketone (PEKK), have received less attention until now. The present work deals with joining PEKK parts by LTW in amorphous over semi-c...

The present paper addresses experimental and numerical investigations of a Large Scale Additive Manufacturing (LSAM) process using polymers. By producing large components without geometrical constraints quickly and economically, LSAM processes have the capability to revolution- ize many industries. Accurate prediction and control of the thermal his...

Laser transmission welding is a widely used process for joining thermoplastics. Of the two materials involved in the welding process, one should be transparent/semi-transparent to laser wavelength, and the other absorbent to the same wavelength. A laser beam is transmitted through the transparent material and is absorbed at the interface of the two...

In this work, a numerical method is presented in order to simulate the deposition of molten polymer bead onto a substrate and its cooling down in the large-scale extrusion-based additive manufacturing process. The polymer flow is treated as a single-phase flow with a free surface. This method reduces the computation time without loss of accuracy as...

An inverse method for determining the in-plane effective thermal conductivity of porous thermoplastics was implemented by coupling infrared thermography experiments and numerical simulation of heat transfer in straight fins having temperature-dependent convective heat transfer coefficient. The microstructure heterogeneity of extruded polyethylene f...

Transmission laser welding (TLW) is an environmentally friendly and versatile process for assembling polymeric parts. Welding by transmission requires the upper element to be transparent to the laser wavelength whereas the inferior part is absorbent to the same wavelength. Thus, the energy of the laser beam is concentrated at the interface, allowin...

This paper presents a coupled two-phase flow model for simulation of submerged flow bridge scour under dam-break flows considering the sediment-fluid interaction. The Smoothed Particle Hydrodynamics (SPH) method is employed to simulate the sediment and fluid movements based on the Newtonian and non-Newtonian fluids, respectively, in the framework o...

Laser Transmission Welding process (LTW) is a well know technic for polymer welding. This technic can also be applied to thermoplastic glass fiber composite (polymer + continuous glass fibers). But in this case two phenomenon occur and are able to make the welding in a poor quality: light absorption and light scattering. The two phenomenon occurrin...

This paper addresses heat distribution issues in Fused Filament Fabrication (FFF) process. 3D Numerical simulations and experimental investigations are performed during additive manufacturing of parts by FFF process. The transient numerical simulations of the filament temperature field are based on the finite difference method. Experimental measure...

Although good progress was made by two international benchmark exercises on in-plane permeability, existing methods have not yet been standardized. This paper presents the results of a third benchmark exercise using in-plane permeability measurement, based on systems applying the radial unsaturated injection method. 19 participants using 20 systems...

The aim of this paper is to develop a cost-effective, efficient and fast experimental optical method to predict the optical properties (extinction coefficient) of semi-transparent glass-fibre-reinforced polymer composites. The extinction coefficient takes into account the effects due to the absorption and the scattering phenomena in a semi-transpar...

A numerical study of flow behavior and the heat transfer process of reactive polymer in reactive rotational molding systems is carried out using the Smoothed Particle Hydrodynamics method (SPH). The flow of reactive polymer during rotational molding inside a horizontal rotating cylinder is modeled as the slightly compressible viscous fluid flow and...

The purpose of this paper is to develop a cost-effective, efficient and quick to implement experimental optical method in order to predict the optical properties (extinction coefficient) of semi-transparent polymer composites. The extinction coefficient takes into account the effects due to the absorption and the scattering phenomena in a semi-tran...

Tracking the variability of natural fiber-based fabrics properties, such as local areal weight, fiber volume fraction, and therefore permeability, is crucial to optimize the parts processing of the bio-composites. This paper aims at developing a cost-effective and efficient optical method in order to predict the permeability of flax fabrics used in...

An inverse method for determining the in-plane effective thermal conductivity of porous thermoplastics was implemented by coupling infrared thermography experiments and numerical solution of heat transfer in straight fins having temperature-dependent convective heat transfer coefficient. The obtained effective thermal conductivity values were compa...

The importance of the absorption phenomenon occurring into the semi-transparent substrate of reinforced fiber thermoplastic, during the Laser Transmission Welding process (LTW), was examined. A (3D) transient thermal model of LTW was developed. First, the energy distribution coming from the laser irradiation was assessed. Ray tracing techniques all...

This study is dedicated to the development of a numerical finite-element solution to determine the effective thermal conductivity of extruded polymeric foam with different levels of open and closed porosity. The implemented numerical method is derived from periodic homogenization techniques used for the simulation of laser welding of composite mate...

In this study, the effects of the welding temperature field developed during the infrared assembly process on the joining properties of glass fibre reinforced polycarbonate/unreinforced polycarbonate with carbon black were investigated. The temperature field and the contact time govern together the quality of the adhesion at the welding interface....

In this study, the effects of the welding temperature field developed during the infrared assembly process on the joining properties of glass fibre reinforced polycarbonate/ unreinforced polycarbonate with carbon black were investigated. The temperature field and the contact time govern together the quality of the adhesion at the welding interface....

In this paper, experimental measurements are performed to confirm the global analytical model (refraction and absorption phenomena) presented in the previous work. Initially, an experimental approach to the estimation of the laser beam spread in a semi-transparent composite and at interface (width of the output beam) subjected to an incident heat f...

Thermoplastic composites for structural applications are under growing development from the aerospace (carbon fibers with PEI, PPS or PEEK matrices mainly) to the automotive industry (glass and carbon fibers with PP, PA). The plastic deformation they can provide and the assembly facilities through welding techniques are well appreciated. Among the...

A new analytical formulation of governing equations for hydro-mechanical coupled problem during single sided molding processes such as vacuum infusion (VI) is presented in this study. The main complexities of VI modeling are the non-linear pressure profile and thickness evolution during filling. The research is focused on the relationship between f...

In the present study, thermophysical and optical characterization of UD thermoplastic composites materials have been investigated. Knowledge of these parameters is of utmost importance to better understanding of any process that involves laser processing of materials. These properties play an important role during the simulation of the welding proc...

In this paper, experimental measurements are performed to confirm the global analytical model (refraction and absorption phenomena) presented in the previous work. Initially, an experimental approach to the estimation of the laser beam spread in a semi-transparent composite and at interface (width of the output beam) subjected to an incident heat f...

A numerical study is developed to predict of flow behavior and heat transfer processes during rotational molding of polymer powder by using Discrete Element Method (DEM). The aim of this study is to model different forms, the evolution of mixing and segregation and the evolution of heat transfers in polymer powder. Influence of physical and thermal...

In previous studies [1, , we have presented a detailed formulation of a macroscopic analytical model of the optical propagation of laser beams in the case of unidirectional thermoplastic composites materials. This analytical model presented a first step which concerns the estimation of the laser beam intensity at the welding interface. It describes...

Recently, natural fibers are attracting great interest from automotive industry by virtue of their environmental friendliness as well as high specific stiffness. Liquid composite molding (LCM) processes have a high potential as a manufacturing process of natural fiber reinforced composite structures by dint of high fiber volume fraction to enhan...

Structural composite manufacturing relying on Liquid Composite Molding technologies is strongly affected by local variability of the fibrous reinforcement. Optical techniques using light transmission are used and allow field measurements of areal weight (and fibre volume fraction) of glass fibre reinforcement. The coupling of obtained areal weight...

In industry, resin flow prediction is a real challenge, because filling defects, such as dry spots and porosities, can dramatically degrade the mechanical properties of the shaped part. The present contribution investigates the use of the boundary element method for the numerical simulation of resin flow in liquid composite molding processes. Due t...

Analytical and numerical models for laser beam scattering in the thermoplastics composites are presented. The numerical model is based on Ray Tracing, an optical method to compute the optical propagation of laser beams in inhomogeneous media with spatially varying dispersion of the refractive index. In this study, only the case of unidirectional th...

The whole stretch blow-moulding process of PET bottles is simulated at the usual process temperature in order to predict the elastic end-use properties of the bottles. An anisotropic viscoplastic constitutive law, coupled with microscopic variables, is identified from uniaxial tensile tests performed at different strain rates and temperatures. The...

Thermoplastics composites offer the possibility to use welding techniques for joining, due to the ability of the polymer constituting the matrix to melt when exposed to sufficient thermal energy. Laser technology is a good alternative for continuous joining of thermoplastics composites structures. However, presence of continuous fibers at a high fi...

Thermoplastics composites offer the possibility to use welding techniques for joining, due to the ability of the polymer constituting the matrix to melt when exposed to sufficient thermal energy. Laser technology is a good alternative for continuous joining of thermoplastics composites structures. However, presence of continuous fibers at a high fi...

An efficient numerical approach is presented for the simulation of mold filling process with random fibrous permeability as input. Suitable dimension-reduction techniques are employed to represent all the random fields in the physical system. The required accuracy in tracking the moving resin flow front is guaranteed by the Level Set Method (LSM)....

Stretch blow molding or thermoforming processes includes an infrared heating stage of the thermoplastic preform by infrared heaters. The knowledge of the temperature distribution on the surface and through the thickness of the preform is important to make good prediction of thickness and properties of the manufactured parts. Currently in industry,...

This paper focuses on RAYHEAT, a software based on the ray tracing method, developed in order to simulate the InfraRed (IR) heating of semi-transparent polymers. In this study, RAYHEAT is used to simulate the IR heating step of a PET preform for the Stretch-Blow Moulding (SBM) process. The general principle of the method is to discretize, into a se...

Thermoforming process include a heating stage of the thermoplastic specimen by infrared heaters. The knowledge of the temperature distribution on the surface and through the thickness of the preform is important to make good prediction of thickness and properties of the manufactured part. Currently in industry, the fitting of the process parameters...

The stretch-blow molding process of polyethylene terephthalate (PET) bottles generates some important modifications in the mechanical properties of the material. Considering, tire process temperature (T > T(g)) that is usually used, the material exhibits a very high viscosity and involves a strain hardening effect associated with the microstructure...

In this thesis, we propose to develop a tool to design the stretch blow-molding process of PET bottles. We have implemented a software of numerical simulation which uses a meshless method : the constrained natural element method (C-NEM). In order to provide this software, we modeled the mechanical behaviour of PET by a non linaire anisotropic model...

The stretch-blow molding process of poly(ethylene terephthalate) bottles generates some important modifications in the mechanical properties of the material. Considering, the range of temperature (T > Tg ) that is usually used, the material has a very high viscosity and shows a strain hardening effect linked to the microstructure evolution. A simpl...

Dans cette thèse, nous proposons de développer un outil de conception pour la mise en forme des bouteilles en PET par le procédé d'étirage-soufflage. Nous avons implémenté un logiciel de simulation numérique qui utilise une méthode meshless : la méthode des éléments naturels contraints (C-NEM). Pour alimenter le logiciel nous avons modélisé le comp...

The stretch-blow molding process of poly (ethylene terephthalate) bottles induces some important modifications in the mechanical properties of the material. Considering the process temperature ($T > T_{g}$) that is usually used, the material presents a very high viscosity and shows a strain hardening effect linked to the microstructure evolution. A...

Le soufflage des bouteilles en polyéthylène téréphtalate (PET) génère des modifications importantes des propriétés mécaniques du matériau. Ce procédé de mise en forme est réalisé alors que le matériau se trouve à des températures légèrement supérieures à la température de transition vitreuse. Les modifications de propriétés en cours d'étirage sont...

The stretch-blow moulding process of poly (ethylene terephthalate) bottles generates some important modifications in the mechanical properties of the material. Considering, the process temperature (T > Tg) that is usually used, the material has a very high viscosity and shows a strain hardening effect linked to the microstructure evolution. A simpl...

The stretch-blow moulding process of poly(ethylene terephthalate) bottles generate some important modi fications in the mechanical properties of the material. Consider ing, the process temperature (T > Tg) that is usually used, the material has a very high viscosity and shows a strain hardening effect linked at the microstructure evolution (induced...