Christophe Bouvet

Christophe Bouvet
Institut Supérieur de l'Aéronautique et de l'Espace (ISAE) | ISAE · Institut Clément Ader, Toulouse, France

Professor

About

180
Publications
32,382
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3,205
Citations
Introduction
Christophe Bouvet currently works at the ISAE-SUPAERO and at ICA (Institut Clément Ader), Toulouse, FRANCE. Christophe does research in Mechanics of Composite.
Additional affiliations
December 2009 - present
Institut Supérieur de l'Aéronautique et de l'Espace (ISAE)
Position
  • Professor (Full)

Publications

Publications (180)
Article
An experimental study has been carried out to describe the evolution of the failure load relative to the maximum misalignment angle of curved carbon–epoxy laminates with out-of-plane wrinkle defects for a large range of misalignments. L-angle specimens with different levels of fibre wrinkling were manufactured and tested in four-point bending tests...
Article
This paper presents the development of a new 3D finite element model for the simulation of UD composites materials under crushing, at the mesoscale. It is based on the Discrete Ply Model (DPM), enhanced with a new damage law to represent compression at constant stress due to localised crushing and its propagation from one element to another. The mo...
Article
The present work was aimed at investigating the failure of quasi-isotropic fibers reinforced thermoplastic laminates solicited at different testing temperatures. Single-edge-notch bending (SENB) tests were conducted at room temperature (RT) and at a temperature higher than the glass transition temperature (Tg) to investigate the influence of failur...
Conference Paper
Full-text available
The VIRTUOSE project aims at reducing the number of experiments from the test pyramid that is necessary to certify aeronautical composite structures. Thanks to the VERTEX test rig [1, 2], a combined loading of tension/compression-shear-pressure can be applied on large specimens (400*400mm2 area of interest). Around the world, only few test rigs all...
Article
Full-text available
To decrease development costs of aeronautical composite structures, industrials and academic researchers are turning to “virtual testing” methods. To help achieve this objective, a new methodology has been developed at the Institut Clément Ader. It is based on a complex loading test rig for technological specimens (more representative than the usua...
Article
Full-text available
The present study investigates, experimentally and numerically, the tensile behavior of copper-clad aluminum composite wires. Two fiber-matrix configurations, the conventional Al-core/Cu-case and a so-called architectured wire with a continuous copper network across the cross-section, were considered. Two different fiber arrangements with 61 or 22...
Article
Sandwich structures are widely used in many industrial applications and especially in light aviation. The local buckling phenomenon named “wrinkling” is one of the primary causes of compressive failure of such structures. Its calculation is a difficult practical problem since this phenomenon cannot be captured by the GFEM (Global Finite Element Mod...
Conference Paper
Dans ce travail, un modèle numérique simple constitué d'un critère de rupture basé sur la mécanique de la rupture est testé pour tenir compte de la dissipation du taux de restitution d'énergie critique en mode d'ouverture (mode I) associée à la rupture de fibres. Les plaques stratifiées utilisés dans cette étude sont obtenus par thermocompression....
Article
The translaminar fracture behavior of three composite laminates, based on thermoplastic matrix PEEK reinforced by a woven carbon fibers obtained by consolidation process, has been studied by means of Compact Tension (CT) and Compact Compression (CC) tests. An orthotropic laminate and two quasi-isotropic laminates, have been tested at room temperatu...
Article
Plant fiber properties, such as morphological and mechanical, are characterized by a large dispersion. Thereby, a statistical analysis is needed to obtain consistent results. An experimental study, conducted on 50 flax yarns, shows that the flax yarn properties (Young's modulus, tensile strength and diameter) follow Gaussian distributions. This app...
Article
Full-text available
Recent advancements in composite production and processing are making thermoplastics a viable option in a wider array of aerospace applications. In particular, Carbon Fibre Reinforced Plastics (CFRP) with thermoplastic resin are believed to have better damage tolerance properties than thermosets. However, few studies have been conducted regarding t...
Article
Full-text available
This study aims at examining the impact behavior of hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic quasi-isotropic laminates. An instrumented Charpy pendulum is specifically designed to estimate its capability to perform low velocity impact tests. Through the comparison of different impact methods (Q...
Article
Full-text available
This paper presents a review of the issues concerning sandwich structures for aeronautical applications. The main questions raised by designers are first recalled and the complexity of sandwich structure design for aeronautics is highlighted. Then a review of applications is presented, starting with early examples from the 1930s and the Second Worl...
Article
Composite failure phenomena remain complex and lead to over-size structures in many industries, involving long and costly experimental campaigns. Numerical approaches are a good alternative to decrease sizing costs. The Discrete Ply Model developed in Institut Clément Ader over these last ten years shows good results in simulation of impact and com...
Article
Full-text available
Ever growing applications of flax fiber-reinforced composites (FFRCs) and their suitability for structural uses involve implementing the design and failure criteria for these composites. Translaminar fracture is one of the primary failure modes of unidirectional (UD) fiber-reinforced composites, and measuring it is essential for design purposes and...
Article
The purpose of this study is to complete a previous quasi-static experimental campaign on the energy absorption performance of composite tubes with the influence of the dynamic effect. Various hybrid composite tubes, involving unidirectional and braided plies with various materials and stacking sequences, were tested both in quasi-static and in dyn...
Article
Full-text available
The development and certification of aeronautical composite structures is still largely based on the pyramid of tests. This approach is extremely costly in terms of number of tests, especially at the level of coupons. Moreover, these tests are highly conservative, under uniaxial loading, and do not represent the actual behavior at structure scale....
Article
The potting failures of inserts in a sandwich structure are analyzed. The case of inserts potted with syntactic foam is investigated. First, the influence of defects is discussed. Then, experiments are performed to determine the tension and compression behavior of the syntactic foam. Later, a specific technological pull-out test was performed, whil...
Conference Paper
Full-text available
The design of very lightweight aircraft sandwich structured composites requires a deep knowledge to tackle the failure modes. In this paper, we focus on the wrinkling which may be the primary cause of failure of such structures. Currently, lightweight sandwich structured composites are more and more used in the aeronautics industry and extend to pr...
Article
Full-text available
Machining of composite materials is a challenging task due to the heterogeneity and anisotropy of composite structures. The induced defects reduce integrity of the machined surface as well as the loading capacity of the composite structure in service. Therefore, it is necessary to quantify the damage induced during trimming and correlate the qualit...
Article
Highly curved laminated parts are used at the junction between two different perpendicular panels on aircraft primary structures. Usually, these laminates fail by delamination due to a bending moment, which appears when the part is loaded. The bending moment tries to flatten the part and out-of-plane tensile stresses are generated in the curvature....
Article
Full-text available
The purpose of this study is to evaluate and compare the ability of various composite structures to dissipate the energy generated during a crash. To this end, circular composite tubes were tested in compression in order to identify their behavior and determine their absorbing capabilities using the specific energy absorption (energy absorbed per u...
Conference Paper
Le comportement en rupture translaminaire de trois composites stratifiés, à matrice thermoplastique PEEK renforcée par un tissu de fibres de carbone obtenus par thermo-compression, a été étudié au moyen d’essais Compact Tension (CT) et Compact Compression (CC). Un stratifié orthotrope et deux stratifiés quasi-isotropes ont été testés à température...
Article
This paper presents an experimental investigation of compression on pristine specimens and the compression after impact (CAI) response of wood-based sandwich structures. Nine different types of sandwiches, made with plywood core and different aluminum or composite (carbon or glass or flax fiber) skins, are studied. Impact energy levels were fixed a...
Article
This paper is intended to test the capacity of a simple model based on fracture mechanics concepts to predict the ultimate strength of notched hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic (TP) quasi-isotropic (QI) laminates under different temperature conditions. In such materials, translaminar fai...
Article
Full-text available
The aim of this paper is to study the influence of the process parameters (cutting speed and feed) of the conventional trimming on cutting forces, machining temperatures, tool wear and machining quality of Carbon Fibers Reinforced Plastics (CFRP) using PCD tool. The machining quality was characterized using three different techniques such as Scanni...
Article
The objective of this paper is to understand and study the effect of morphological parameters on the shear stiffness of an entangled cross-linked fibrous material made with carbon fibres where some of the contacts are bonded by the epoxy resin. This current work presents a 3D finite element model using ABAQUS/Standard in order to characterize the m...
Article
An end notched flexure (ENF) test was used to study the effect of growth stability on mode II interlaminar fracture toughness (GIIC) of a carbon/PEEK composite. The instability of the ENF test was used to induce both stable and unstable crack growth with a static loading. Two techniques were used to evaluate mode II fracture toughness: the traditio...
Chapter
Full-text available
Composite materials particularly fiber-reinforced plastics (FRPs) have brought remarkable advances in various engineering sectors because of their excellent mechanical properties. Ranging from space applications to consumer products, their demand is ever increasing, and to bridge this supply gap, constant endeavor is focused on optimizing their pro...
Article
The fracture behavior of hybrid carbon and glass fiber woven-ply reinforced polyether ether ketone thermoplastic quasi-isotropic laminates is investigated. Single-edge-notch bending and single-edge-notch tensile tests were conducted at room temperature and at a temperature higher than the glass transition temperature (Tg) to study the influence of...
Article
The fracture behavior of hybrid carbon and glass fiber woven-ply reinforced polyether ether ketone thermoplastic quasiisotropic laminates is investigated. Single-edge-notch bending and single-edge notch tensile tests were conducted at room temperature and at a temperature higher than the glass transition temperature (Tg) to study the influence of b...
Article
The analysis of an entangled cross-linked fibrous material at low deformation is explored as way of predicting the shear behaviour, especially the shear hysteresis. This paper presents a 3D finite element model to characterize the carbon fibre network rigidified by epoxy cross-links. The morphology of the representative volume element (RVE) is stud...
Article
Composites are known to be vulnerable to out-of-plane loading such as impact. Investigating the residual properties of the laminate as a function of damage detection is the main purpose of impact damage tolerance design in aeronautics. As a good alternative to experimental campaigns, numerical approaches would lead to saving of time. The model deve...
Conference Paper
The size of the chips generated during the machining of composites is influenced by the machining parameters. Specifically for CFRP made of thermoset matrix, chips are broken down to minute sizes and suspended in the air. Due to the lighter weight, the chips in the form of dust particles can be emitted in the air which can be inhaled by operators i...
Article
In this work, a modelling strategy based on damage mechanics is presented for Nomex honeycomb core. The proposed approach is based on the experimental analysis presented by the authors in [1] and consists of the decoupled modelling of the buckling and collapse of cells for the HRH-78 Nomex honeycomb core with two damage parameters. The proposed app...
Conference Paper
Full-text available
In this research, the virtual testing approach is used to study the failure of inserts in sandwich structures. First, a reduced F.E. model of inserts is presented, which includes nonlinear aspects of the materials such as the buckling and collapse of the honeycomb cells, the failure of the potting and the matrix failure of the skins. These model ar...
Article
A new entangled cross-linked material was recently developed in order to present a new core material that can resolve the drawbacks of the honeycomb. The optimization of entangled carbon fibres requires a deep understanding of the influence of the parameters of a fibre network on its macroscopic behaviour. This paper presents a 3D finite element mo...
Article
This work is a contribution to the understanding of the nonlinear shear behaviour caused by cell postbuckling in Nomex honeycomb cores. First, an experimental benchmark study was made of different designs for the shear testing of honeycomb cores. Then, several test specimens were fabricated and tested, a 3D DIC system being used to measure and reco...
Article
In this paper, numerical simulation is developed in order to analyze the failure of a noncircular composite chainring, and teeth damage is especially detailed. Simulation consists of the chainring and a part of the metallic chain. To reduce the size of the numerical model only the first 11 rollers are simulated. In order to validate the numerical s...
Article
The paper presents an experimental analysis to determine the teeth failure of noncircular composite chainring. A noncircular carbon/epoxy chainring with a specific stacking of 11 plies is studied. In a first step, a quasi-static tensile test is realized on the chain and on the chainring to determine their strength. As the damage of composites is a...
Conference Paper
Trimming is the first and foremost machining operation done on composite structures (CFRPs) post demolding to remove excess resin overflows and jagged edges. Due to inherit heterogeneity of composite laminates and the anisotropy of carbon fibers, this machining operation is more difficult compared to that of metallic materials. In fact, machining o...
Article
Full-text available
The behavior of composite laminates subject to notch based stress concentrations is difficult to apprehend, especially the mechanisms of damage progression leading to total failure. Numerical and experimental investigations were carried out on three different stacking sequences of notched, thin ply carbon/epoxy laminates. This paper presents a comp...
Conference Paper
Full-text available
Du fait de leur légèreté et propriétés mécaniques intéressantes, l'utilisation des matériaux composites dans le domaine aéronautique est de plus en plus fréquente, même pour la réalisation de parties structurales, principalement conçues à partir d'ensembles métalliques jusqu'à présent. Allant en ce sens, l'objet de cette étude est la réalisation et...
Chapter
This chapter focuses on the study of the cohesive forces of the solid S, at point M and which is in equilibrium under the action of external forces. There are three types of external forces: concentrated forces, surface forces, and volume forces. The chapter derives the torsor of internal forces and the center of gravity, where the torsor notion ma...
Chapter
Under the action of external forces, S becomes S' and M becomes M', where S is a solid and M(x, y, z) is a point of S. This is called the displacement vector of the point M. There are two points of S: M and N, which are displaced to M' and N' after stress and n the unit vector. This is called unit strain in M according to n. This strain must remain...
Chapter
The philosophy of sizing an aeronautical structure could be summarized as: no damage or permanent deformation is permitted in service, namely for realistic loads or even those less than or equal to the limit loads (LL); the structure must remain whole for a test load, namely for very improbable loads or even those less than or equal to the ultimate...
Chapter
Behavior law is the relation that links the stress and strain. Evidently, it depends on the material and the external conditions. A material is said to be homogeneous if it behaves the same behavior at each point. A material is said to be isotropic if it behaves in the same way in all directions. This chapter focuses on isotropic homogeneous materi...
Chapter
The study of deformable solids consists of determining the relation between the displacement and the strain, the equilibrium equation, and the material's behavior law at each point of the structure. Once the stress, strain and displacement fields have been determined, this chapter applies the sizing criterion to the structure (rupture criterion, no...
Chapter
An aeronautical structure is sized under the ultimate loads (UL), while accounting for the plasticity. This chapter notes a plastic strain localization phenomenon which starts at the maximum stress point and which is called necking, by observing the shape of the sample in a tension test. It shows that the stress state in the necking area is no long...
Chapter
This chapter presents a diagram that defines state 1 what is called the initial state or stress-free state, and state 2 called the deformed states, which is under the effect of external forces. It gives the formula for the kinetic energy theorem between states 1 and 2. In the mechanics of deformable solids, the internal energy only depends on the s...
Chapter
This chapter addresses the two main materials used in aeronautical structures, i.e. aluminum and carbon/epoxy composite. Together, these materials comprise approximately 70% of the structural mass of a commercial aircraft such as the Boeing 787. The other structural materials used are different composite materials based on fiberglass, sandwich stru...
Chapter
This chapter provides practice exercises based on the mechanics of aeronautical solids and materials including Rosette analysis, compression of an elastic solid, gravity dam, shear modulus, modulus of a composite, and torsional cylinder. It consider an aluminum cube of dimension a subjected to compression stress in the x-direction to explore the st...
Chapter
This chapter provides solutions to the practice exercises asked in the previous chapter based on the mechanics of aeronautical solids and materials, including Rosette analysis, compression of an elastic solid, gravity dam, shear modulus, modulus of a composite, and torsional cylinder. It shows that the maximum normal stress is necessarily the maxim...
Article
Impact damage tolerance of hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic (TP) laminates obtained by consolidation process is investigated. Service temperature being one of the most important parameters to screen TP or thermoseting matrix for aeronautical purposes, impact testing at room temperature...
Article
In aeronautics, honeycomb sandwich structures are widely used for secondary structures such as landing gear doors, flaps or floors, and for primary structures in helicopters or business jets. These structures are generally joined by using local reinforcements of the insert type. In the present study, 50 J low velocity impact tests were performed on...
Chapter
Low-velocity impact is one of the most critical load factors for composite laminates. Indeed, for structures submitted to low-energy impacts or small-object drops, such as tools during assembly or maintenance operations, composite laminates reveal a brittle behavior and can undergo significant damage in terms of matrix cracks, fiber breakage, or de...
Article
The aim of this work is to increase the study of the notch translaminar propagation of the woven structures, using the InfraRed Thermography (IRT). A test of notch propagation under quasi-static traction was developed and used to study the failure phenomena on two different draping sequences. For each study, a local estimation of dissipated energie...
Article
Full-text available
This paper presents a Non-Destructive Testing (NDT) method based on the penetration properties of terahertz (THz) waves. A CW raster-scanning THz imaging setup, using a 3.8 THz Quantum Cascade Laser as a source, is used to perform NDT of polypropylene/polypropylene composite samples. Results from transmission and reflection THz imaging are compared...
Article
Composite structures are particularly vulnerable to impact which lowers drastically theirs residual strength. In particular, the edge impact on composite stiffener is known as a critical factor on the loss of residual compression strength. Then it is necessary to develop a model able to simulate impact and compression after impact in order to numer...
Article
Full-text available
Numerical and experimental investigations were carried out on the size effect in notched carbon/epoxy laminates. This paper presents a computational study of scaled open-hole tensile tests using the Discrete Ply Modeling (DPM) method, which has already proven efficient on both in-plane and out-of-plane loading cases, such as pull through, low veloc...
Article
This paper presents an experimental study of CAI (compression after impact) of tapered composite laminate. Two types of layup with thickness changing from 4 mm to 6 mm are considered. A new CAI testing rig, suitable for the specimens and a brief description of impact damage are presented first. Then, the behavior of impacted specimens under compres...
Article
Full-text available
Infrared thermography was used to study damage developing in woven fabrics. Two different experiments were performed, a ±45° tensile test and a rail shear test. These two different types of tests show different damage scenarios, even if the shear stress/strain curves are similar. The ±45° tension test shows matrix hardening and matrix cracking wher...
Article
Finite Element Analysis of low velocity/low energy edge impact has been carried out on carbon fiber reinforced plastic structure. Edge impact experimental results were then compared to the numerical “Discrete Ply Model” in order to simulate the edge impact damage. This edge impact model is inspired to out-of-plan impact model on a laminate plate wi...