IRT Jules Verne

Bouguenais, France

IRT Jules Verne

Bouguenais, France

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Rolere S.,IRT Jules Verne | Rolere S.,CNRS Le Mans Institute of Molecules and Materials | Coulon J.-F.,ECAM Rennes Louis de Broglie | Poncin-Epaillard F.,CNRS Le Mans Institute of Molecules and Materials
European Polymer Journal | Year: 2017

Perfluorononanoic acid (F17) was grafted to an epoxy resin. The virgin epoxy resin and the fluorinated epoxy resin were cured at various temperatures. Both air-resin and substrate-resin interfaces of the cured materials were characterized in terms of: (i) free surface energy, (ii) surface composition, evaluated using angle-resolved X-ray photoelectron spectroscopy (AR-XPS). Fluorine proportion was quantified at probing depths of about 4.5 and 9 nm. The curing temperature highly influenced the diffusion of the perfluorinated chains towards both interfaces. Depending on the curing conditions, very low free surface energies (17 mJ/m2) due to high fluorine concentrations (fluorine/carbon ratio = 0.6) were measured at the air-resin interface. However, the F17 diffusion towards the substrate was also observed and led to important fluorine concentrations (F/C up to 0.4). Finally, a two-step curing procedure was used for monitoring the F17 diffusion during the curing, illustrated by an accumulation of fluorine atoms at both interfaces. A non-linear relation was highlighted between the surface energy drop and the fluorine content measured by AR-XPS. © 2017


Lascoup B.,IRT Jules Verne | Perez L.,CNRS Nantes Thermocinetique Lab | Autrique L.,University of Notre Dame
Composites Part B: Engineering | Year: 2014

A new method dedicated to macroscopic-like defect localization in composite materials is presented in this paper. The proposed method is based on non intrusive measurements of the sample temperature resulting from a local periodic low energy heating. In such an approach, the low temperature increases of the investigated material avoid damages which can occur with usual flash techniques. Since thermal waves propagation is modified due to the heterogeneity induced by the defect, analysis of both modulus and phase lag spatial distributions provides relevant knowledge. Up to now, macroscopic-like defect detection based on local periodic heating has not been widely investigated. Thus, differences between the global approach and the local approach have to be pointed out in order to verify the local method's attractiveness. A mathematical model based on complex temperature is developed and provides a relevant predictive tool. In several configurations interest of local periodic heating is highlighted. For example, while several defects are included in the sample, the method capability to distinguish one from each other is shown considering a scanning approach. In order to validate these results, an experimental device has been developed. Several non destructive inspections are performed and defect detection is achieved using an infra-red camera providing observations of the sample surface. © 2013 Elsevier Ltd. All rights reserved.


Ruckert G.,DCNS S.A. | Chargy M.,IRT Jules VERNE | Chargy M.,STX FRANCE SA | Cortial F.,DCNS S.A. | Jorez F.,STX FRANCE SA
Advanced Materials Research | Year: 2014

FSW process has been evaluated on three shipbuilding steels (DH36, S690QL and 80HLES steels) by fully penetrated butt welds on 8mm thick plates. Non destructive tests were carried out to highlight the presence of intrinsic defects known for the welding process (eg kissing bond). The validated inspection methodology (volume and surface testing) confirm the integrity of welds and the absence of geometrical defects for examinations and mechanical tests as part of a qualification procedure. © (2014) Trans Tech Publications, Switzerland.


Gagliardini L.,IRT Jules Verne | Caro S.,French National Center for Scientific Research | Gouttefarde M.,French National Center for Scientific Research | Wenger P.,French National Center for Scientific Research | Girin A.,IRT Jules Verne
Mechanisms and Machine Science | Year: 2015

The research work presented in this paper introduces a Reconfigurable Cable Driven Parallel Robot (RCDPR) to be employed in industrial operations on large structures. Compared to classic Cable-Driven Parallel Robots (CDPR), which have a fixed architecture, RCDPR can modify their geometric parameters to adapt their own characteristics. In this paper, a RCDPR is intended to paint and sandblast a large tubular structure. To reconfigure the CDPR from one side of the structure to another one, one or several cables are disconnected from their current anchor points and moved to new ones. This procedure is repeated until all the sides of the structure are sandblasted and painted. The analysed design procedure aims at defining the positions of the minimum number of anchor points required to complete the task at hand. The robot size is minimized as well. © Springer International Publishing Switzerland 2015.


Ghnatios C.,IRT JULES VERNE | Chinesta F.,École Centrale Nantes
Computational Plasticity XII: Fundamentals and Applications - Proceedings of the 12th International Conference on Computational Plasticity - Fundamentals and Applications, COMPLAS 2013 | Year: 2013

Nowadays, composite materials are replacing metallic ones thanks to their excellent mechanical performances and reduced weight. However, many difficulties are encountered during composite forming processes. Infact, autoclave curing process is too expensive and limits the part size to the autoclave dimensions. Out-Of-Autoclave processes reduce substantially the cost of forming processes. However, the absence of autoclave pressure in out-of-autoclave manufacturing processes leads nowadays to high porosity and poor consolidation at the interface between the tows[1]. Moreover, the effect of the process parameters on the consolidation is still unknown and thus controlling the final parts quality is not obvious. Despite the high potential offered by the Out-of-Autoclave processes, only few researches has been made in the last few years, in order to quantify the consolidation of the tows while using such processes[2]. Infact, only few models addressing void dynamics in thermoplastic composites has been carried out[3,4]. In this work, we are using a novel coupled approach involving modeling and simulation in order to quantify the consolidation in Out-of-Autoclave processes. Advanced model reduction techniques (POD,PGD...) are employed in order to predict thermal fields during manufacturing processes and coupled to the subsequent squeeze flow.


Younes W.,IRT Jules Verne | Giraud E.,LAMPA | Dal Santo P.,LAMPA
Key Engineering Materials | Year: 2015

Anisotropic behavior at high temperature of an Aluminum-Lithium alloy was studied. Mechanical tests at a temperature of 350°C and a strain rate of 10-2 s-1 were carried out on samples taken at different angles with respect to the rolling direction of the sheet. Two plasticity criteria (HILL48 and HU2005) were identified and implemented in ABAQUS to predict the anisotropic behavior of the alloy for other angles. Results show that: (i) the alloy exhibits an anisotropic behavior at high temperature and some recrystallization occurs during plastic deformation; (ii) the coefficients of anisotropy depend on strain level and (iii) HU2005 criterion allows describing the behavior of the alloy at high temperature. © (2015) Trans Tech Publications, Switzerland.


Tardif X.,IRT Jules Verne | Pignon B.,CNRS Nantes Thermocinetique Lab | Boyard N.,CNRS Nantes Thermocinetique Lab | Schmelzer J.W.P.,University of Rostock | And 3 more authors.
Polymer Testing | Year: 2014

The recently developed fast scanning differential calorimetry is used for the first time to determine the crystallization kinetics of Poly(EtherEtherKetone) (PEEK). In our experiments, crystallization is studied in isothermal conditions over a large temperature range from 170 °C to 310°C. Two different measurement protocols were employed. Between 200°C and 300°C the heat flow was directly measured during isothermal crystallization. Outside this temperature range we measured the heat of fusion on heating after interrupted isothermal crystallization. We show that data can be analyzed with the Avrami approach incorporating a term describing secondary crystallization. The crystallization half-times are measured. The Avrami kinetic coefficient KAv associated with primary crystallization is evaluated from isothermal crystallization between 170°C and 310 °C where data were not previously available. The kinetics of crystallization of PEEK has only one maximum located around 230 °C and its Avrami exponent is close to 3, suggesting instantaneous nucleation with subsequent spherical growth. The whole isothermal crystallization process is modeled in terms of Hillier's model since it takes secondary crystallization kinetics into account. Finally, it is shown that the double melting peak behavior observed after isothermal crystallization (below 260 °C) is a consequence of the reorganization process during heating. © 2014 Elsevier Ltd. All rights reserved.


Zghal J.,IRT Jules Verne | Gmati H.,Arts et Metiers ParisTech | Mareau C.,Arts et Metiers ParisTech | Morel F.,Arts et Metiers ParisTech
International Journal of Damage Mechanics | Year: 2016

In this paper, a polycrystalline model is proposed to describe the fatigue behaviour of metallic materials in the high cycle fatigue regime. The model is based on a multiscale approach, which allows the connection of local deformation and damage mechanisms to macroscopic behaviour. To consider the anisotropy of plastic properties, the constitutive model is developed at the grain scale within a crystal plasticity framework. A phenomenological approach, which requires the introduction of a damage variable for each slip system, is used to account for the anisotropic nature of damage. The constitutive model is then integrated within a self-consistent formulation to consider the polycrystalline nature of metallic materials. Finally, the proposed model is used to describe the high cycle fatigue behaviour of a medium carbon steel (0.35% C). With a proper adjustment of material parameters, the model is capable of correctly reproducing fatigue test results, even for complex loading conditions (multiaxial, non-proportional). According to the model, damage is found to be highly localized in some specific grains. Also, while fatigue damage results in a progressive decrease in elastic stiffness at the crystal scale, the elastic properties are not significantly affected at the macroscopic scale. The model is used to study the correlation between energy dissipation and fatigue damage. According to the numerical results, no evident correlation between fatigue damage and energy dissipation is observed. © SAGE Publications.


Lascoup B.,IRT Jules Verne | Lascoup B.,CNRS Acoustic Lab of Du Maine University | Aboura Z.,CNRS Roberval Laboratory (Mechanical Research Unit) | Khellil K.,CNRS Roberval Laboratory (Mechanical Research Unit) | Benzeggagh M.,CNRS Roberval Laboratory (Mechanical Research Unit)
Composites Part B: Engineering | Year: 2014

Improvement of the interfacial toughness of composite sandwich by stitching process is studied in this paper. Double cantilever beam tests are performed to quantify the influence of the presence of the through-the-thickness reinforcement on the skin-core interfacial toughness. The compliance method is used to determine the energy release rate but with a specific formula where an exponential fitting is preferred instead of the power classical fitting. The failure mechanisms for energy absorption are observed and experimental crack travel through the stitches gives an explanation of the particular evolution of the loading curve. An analytical approach is also proposed to predict the overall behavior of the interface. The classical theory of crack propagation is adapted in order to consider the lack of symmetry of the test as the crack does not propagate in the middle of the specimen and to consider additional plate device strengthen the brittle skin of the sandwich. The result of the model is satisfying for the unstitched structure and the range of the predicted critical energy release rate is in accordance with the experimental result. Regarding stitched sandwich, the limits of the model is highlight due to the theory that does not take into account the transverse reinforcement. © 2014 Elsevier Ltd. All rights reserved.


Gagliardini L.,IRT Jules Verne | Caro S.,French National Center for Scientific Research | Gouttefarde M.,Laboratoire dInformatique
IEEE International Conference on Automation Science and Engineering | Year: 2015

Cable Driven Parallel Robots (CDPRs) are a particular class of parallel robots whose legs consist of cables. CDPRs are composed of several components, e.g. winches, pulleys and actuators. The design of a CDPR requires the dimensioning of all these components, according to the task to be performed. The dimensioning of the actuators, the gearboxes and the winches are strictly related to the performances of the CDPR in terms of the platform static and kinematic equilibrium. This paper introduces a new tool, the so called Twist Feasible Workspace (TFW), built in order to analyze the workspace of the platform twists. A pose is said to be twist feasible if the platform of the CDPR can assume a given range of linear and rotational velocities while satisfying the cable speed limits imposed by the actuators and the transmission systems. The size of the TFW is used as an optimization criterion for the dimensioning of the actuators and the winches. © 2015 IEEE.

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