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  • Chung Hae Park
Chung Hae Park

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

PhD

About

110
Publications
19,613
Reads
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1,296
Citations
Additional affiliations
August 2013 - present
IMT Lille Douai
Position
  • Professor (Full)
September 2005 - July 2013
Université du Havre
Position
  • Assistant/Associate Professor
August 2003 - August 2005
LG Chem
Position
  • Engineer
Education
February 2000 - June 2003
Ecole Nationale Supérieure des Mines de Saint-Etienne
Field of study
  • Mechanical and materials engineering
March 1998 - August 2003
Seoul National University
Field of study
  • Mechanical and aerospace engineering
March 1996 - February 1998
Seoul National University
Field of study
  • Mechanical engineering

Publications

Publications (110)
Article
Full-text available
The demand for thermoplastic composites is continuously increasing because these materials offer many advantages over their thermoset counterparts, such as high toughness, long storage time, easy repairing and recycling, and ability to be thermoformed and heat-welded. However, the manufacturing of thermoplastic composite parts using liquid composit...
Cover Page
Full-text available
Most of everyday products and industrial structures are made by the assembly of several parts and therefore contain joints. This is the case for example in the aeronautics, railway or automotive industry where polymer composites become more and more popular as lightweight substitutes of metallic materials. Joining of polymer composites may be achie...
Article
The mechanism of the crack propagation in three dimensional (3D) glass-fiber warp interlock epoxy composites under fatigue loading was investigated via time-lapse micro-computed tomography (µCT) observations. Two different composite samples were manufactured by means of a resin transfer molding (RTM) process under two different constant injection p...
Article
Flax (Linum Usitatissimum L.) fiber composites serve as sustainable replacement for glass fiber composites. Given that these composites are based on natural sources, their performance is susceptible to variation induced by several factors. Hence, ten flax fiber varieties cultivated in two different regions of Belgium in 2017 and 2018 are compared i...
Conference Paper
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...
Article
A novel finite element framework is proposed for the numerical simulation of two phase flows with surface tension. The Level-Set (LS) method with piece-wise quadratic (P2) interpolation for the liquid-gas interface is used in order to reach higher-order convergence rates in regions with smooth interface. A balanced-force implementation of the conti...
Article
Full-text available
A new type of flax fiber-reinforced bio-sourced thermoset composites is investigated to explore their usage in hot and humid conditions and is compared with flax fiber reinforced epoxy composites. Hygrothermal aging of composites is carried out for 40 days at 50 °C and 90%RH. The influence of moisture uptake of composites during aging is evaluated...
Article
Full-text available
Numerical artifacts in the form of spurious oscillations are among the critical issues of Fast Fourier Transfer (FFT) methods for solving multiphase elastic problems such as numerical homogenization, in spite of their computational simplicity and efficiency. In the first part of the present work, it is shown that the irregular discretization of the...
Presentation
Full-text available
The purpose of this work is to provide an objective procedure to conduct qualitative and quantitative analyses based on microcomputed-tomography (µCT) images of different contrast levels which can be obtained in the case of partially impregnated technical preforms of thermoplastic composites. The considered 4D dataset was constructed using absorpti...
Article
In this study, a pattern for an active frequency selective surface (AFSS) applicable to stealth radomes was designed and manufactured. Subsequently, its effectiveness was verified via measurements of its electromagnetic performance, and its mechanical performance was numerically evaluated in an actual flight environment. An AFSS equipped with a PIN...
Article
Full-text available
Among the recent advances made in the analysis and simulation of the mechanical behaviour of composite materials, calculations on a mesoscopic scale make it possible to take into account the internal architecture of a textile and to compute its deformations. The mesoscopic analysis covers the reinforcement behaviour during manufacturing (draping an...
Preprint
A novel finite element framework is proposed for the numerical simulation of two phase flows with surface tension. The Level-Set (LS) method with piece-wise quadratic (P2) interpolation for the liquid-gas interface is used in order to reach higher-order convergence rates in regions with smooth interface. A balanced-force implementation of the conti...
Article
The presence of the tufts has direct influence on the permeability of textile preforms. In this paper, new insights are presented into the mechanisms responsible for changes to the in-plane permeability of tufted preforms according to three different tufting patterns relative to flow direction with a constant tufting distance. The saturated permeab...
Article
This paper presents the first comparative study of fabricating reference porous media with three different additive manufacturing (AM) techniques, namely Fused Deposition Modelling (FDM), Stereolithography (SLA) and HP Multi Jet Fusion (MJF). Various parameters in each step of these 3D printed reference media that contribute to model inaccuracy, in...
Article
Full-text available
The main objectives of this article were to examine the feasibility of high quality laminate (carbon PEKK—Poly-Ether-Ketone-Ketone) manufacturing under low pressure and to analyze the principal phenomena governing the consolidation quality. The quality of laminate was evaluated in terms of the interlaminar shear strength measured by short-beam shea...
Article
This paper presents the first comparative study of fabricating reference porous media with three different additive manufacturing (AM) techniques, namely Fused Deposition Modelling (FDM), Stereolithography (SLA) and HP Multi Jet Fusion (MJF). Various parameters in each step of these 3D printed reference media that contribute to model inaccuracy, in...
Article
Full-text available
The most limiting aspect in liquid composite molding processes is the porosity issue. A successful manufacturing design depends mainly on the accurate prediction of the dynamics of air bubbles while processing composite structures. Especially, while simulating with a constant injection flow rate, where the part is supposed to exhibit a uniform poro...
Article
Full-text available
Absorption-based microcomputed tomography (µCT) scans using polychromatic X-ray sources are frequently used to analyse the microstructure of polymer-matrix composites. Assuming the proportionality between linear X-ray attenuation coefficients and gray levels in the reconstructed µCT images, segmentation techniques can be used to conduct qualitative...
Article
This study sheds light on the effect of resin cure cycle on the tensile properties of unidirectional flax fibers, which are assessed by the impregnated fiber bundle test (IFBT). The experimental protocol combines hand-layup and isothermal compression molding processes to fabricate unidirectional flax composites according to four different curing cy...
Article
We propose an efficient simulation method of three-dimensional (3D) resin flow in laminated preform composed of multiple layers with different permeabilities at each layer. Because of the small thickness of each layer, a huge number of nodes are needed for 3D flow simulation if solid elements are adopted and full 3D simulation takes extremely long...
Conference Paper
De nombreux composites à base de renforts dits 3D, au sens qu'ils incluent des renforts dans l'épaisseur, ont été développés pour surmonter des problèmes inhérents aux stratifiés conventionnels, tels que leur faible résistance à la délamination et leur faible tolérance aux dommages lors de l'impact. Le renforcement dans l'épaisseur peut-être obtenu...
Article
Full-text available
In the case of highly heterogeneous microstructures, such as textile composites herein, conformal FE meshes are difficult to generate for image-based modeling. As an alternative way regular meshing based on the initial image discretization can be used. However, it requires a large number of elements to reduce undesirable effects due to the voxelize...
Article
An efficient experimental method is proposed to measure very low permeability of composite laminated preform fabricated by automated dry fiber tape placement. A new computer program is also presented for the numerical simulation of three dimensional resin flow which is generally impossible by conventional commercial packages due to an extremely hea...
Article
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...
Article
The variational phase-field method is an attractive non-local approach of modeling fracture in heterogeneous materials. However, these materials usually require a fine mesh to resolve the fracture process zone. Consequently, the standard finite element solver becomes cumbersome due to the large number of elements in applications with highly heterog...
Article
Full-text available
We propose a new experimental method using a Hassler cell and air injection to measure the permeability of fiber preform while avoiding a race tracking effect. This method was proven to be particularly efficient to measure very low through-thickness permeability of preform fabricated by automated dry fiber placement. To validate the reliability of...
Article
Full-text available
In Vacuum Infusion (VI) process, used to manufacture large composite structures, the fibrous preform undergoes large deformations during the impregnation due to the use of a flexible vacuum bag. Moreover, the resin pressure difference between the upstream and downstream sides of the preform leads to a non-uniform preform thickness during the mold f...
Article
Full-text available
Presence of the voids in final part made of textile reinforced materials is one of the main process-induced type of defects, which is governed by a set of manufacturing parameters. This work focuses on investigating the effect of voids on mechanical properties of the 3D textile reinforced composites. This study includes the following steps: manufac...
Conference Paper
Full-text available
A multi-scale modelling of 3D woven glass fabric reinforced composites with voids is presented in this work. Two different types of 3D orthogonal layer-to-layer interlocks textile reinforced composites, which are named for simplicity ‘twill 3D’ and ‘satin 3D’, have been addressed in this study. It includes the manufacturing of composite plates with...
Article
Full-text available
Design of structural parts made of 3D textile reinforced materials demands deep understanding of different physical phenomena that must be accounted at the separate steps from manufacturing to exploitation. Complete process relies on numerical methods to resolve multi-scale material modeling and includes quantification of various manufacturing effe...
Article
We propose a new model for the capillary rise of liquid in flax fibers whose diameter is changed by liquid absorption. Liquid absorption into the flax fibers is taken into account in a new modified Washburn equation by considering the mass of the liquid absorbed inside the fibers as well as that imbibed between the fibers. The change of permeabilit...
Article
Un nouveau procédé d’imprégnation directe de renforts textiles en fibres de lin par une matrice thermoplastique permet de fabriquer à bas coût et avec des temps de cycles courts des composites biosourcés à hautes performances mécaniques.
Article
We performed an experimental study to manufacture flax fiber textile reinforced thermoplastic composites by direct impregnation method in a closed mold. To reduce the process time, we adopted compression resin transfer molding resin because of its short flow path during the highly viscous resin impregnation process. Fiber preheating process was int...
Article
Full-text available
A novel static and fatigue modeling of composite structures has been developed by progressive damage simulation at the level of the equivalent (or homogenized) ply and direct post-treatment analysis respectively. The progressive damage mechanisms can be successfully modeled by taking into account the degradation of material properties at mesoscopic...
Article
We investigate the unsaturated resin flow behavior in a dual scale porosity preform by observing the pressure distribution and the void content. The experimental data show that the pressure profile in the unsaturated flow is nonlinear with positive curvature whereas that in the saturated flow is linear as expected from the classical Darcy’s law. To...
Article
This chapter presents numerical modeling and simulation approaches for the resin flow analysis in textile composites manufacturing processes. According to the computational scale, which can be classified by textile microstructure, different governing equations for the resin flow are suggested. Numerical schemes to solve the governing equations are...
Article
The dispersion state of carbon nanotubes (CNTs) is a key parameter to the mechanical properties of nanocomposites. In the previous work, we proposed a method to assess the dispersion state of CNTs in a thermoset polymer matrix by measuring the curing reaction heat. In the present paper, we propose new parameters to represent the degree of CNT dispe...
Conference Paper
Full-text available
MAPICC3D European project aims at developing a novel industrial automated and cost efficient integrated process able to product high performance and quality multifunctional lightweight structural thermoplastic composites. New technologies of upgraded 3D textile preforms produced on line with thermoplastic hybrid yarns from various fibres (E-glass,...
Article
Full-text available
In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has b...
Article
Full-text available
Process induced residual stresses in thermoset composite parts is one of significant issue faced by the industry. Its Modelling is a coupled multiphysics phenomena. Precise information about the chemical shrinkage, thermal expansion coefficient, cure kinetics, heat transfer and constitutive equation are required for an accurate simulation. In this...
Article
Full-text available
We investigate the influence of liquid type on the saturated permeability of natural fabrics in liquid composite molding processes. The permeability of flax woven fabric was characterized with two different liquids which have different viscosity, wettability, and sorption characteristics with flax fiber. From the experimental data, it was observed...
Article
Mesoscopic simulations of the transverse compression of textile preforms are presented in this paper. They are based on 3D FE models of each yarn in contact with friction with its neighbours. The mesoscopic simulations can be used as virtual compression tests. In addition they determine the internal geometry of the reinforcement after compaction. T...
Article
The accurate modelling of residual stress in thermoset composites requires comprehensive consideration of all the phenomena contributing to its formation. These include: chemical shrinkage of matrix due to cross linking of molecules, mismatch of thermal expansion or contraction among fibres and matrix and viscoelastic relaxation during the fabricat...
Article
We present numerical simulation of particle filled resin flow through a fibrous medium taking into account dual scale porosity in LCM (Liquid Composite Molding) processes. During the flow, a strong interaction between the particle motion and the fluid flow takes place at the porous medium wall or at the fiber bundle surface. A model is developed to...
Conference Paper
We present modeling and simulation of air void formation in composite materials manufactured by the Resin Transfer Molding (RTM) process. During the injection of resin into the fiber preform, indeed, air can be entrapped by the resin in the part at microscopic or macroscopic scale. Air voids in composite materials deteriorate the mechanical propert...
Conference Paper
Full-text available
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...
Article
Liquid composite molding processes are widely accepted in the aeronautic industry to manufacture large and complex structural parts. In spite of their cost-effectiveness, void defects created during the manufacturing process are a major issue of these processing techniques because they have detrimental effects on the mechanical performance. The rel...
Article
In the present work, a thermo-visco-elastic model for forming simulation of woven thermoplastic composites has been proposed considering the effect of temperature and the influence of strain rate. This model is implanted into a new membrane finite element, which can consider not only the strain in fibre direction but also the shear caused by the re...
Article
We present numerical simulation of air entrapment in composite materials manufactured by the resin transfer molding (RTM) process. The prediction of air void formation has been an important topic because air voids in composite materials deteriorate the mechanical properties of the part. Two kinds of voids can appear when the resin is injected insid...
Article
It is an important topic to measure the through-thickness permeability of fiber reinforcements as the resin flow in the thickness direction is widely employed in many composites manufacturing techniques. Continuous techniques for the permeability measurement by simultaneous fabric compaction and liquid flow have been recently proposed as an alterna...
Article
Transverse compaction of textile composite reinforcements is an important deformation mode arising during composite forming and manufacture. The mesoscopic simulations of the transverse compression of textile preforms presented in this paper are based on 3D FE models of each yarn in contact with friction with its neighbours. A hypoelastic model bas...
Conference Paper
We present modeling and simulation of air void formation in composite materials manufactured by the Resin Transfer Molding (RTM) process. The prediction of air void formation has been an important topic because air voids in composite materials deteriorate the mechanical properties of the part.It has been found by experimental observations that the...
Chapter
Compression molding is a popular manufacturing technique for composite parts. In particular, the development of high-strength sheet molding compounds drove wide adoption of compression molding process in automotive and appliance applications. In this chapter, we present some advantages and disadvantages of compression molding. We also introduce mol...
Article
Full-text available
This workk concerns the manufacturing of a composite tube using RTM process. During the preforming stage, a woven braid is laid down and stacked on a mandrel so that reinforcement plies form conical shapes with a defined angle. An innovative experimental preforming procedure has been developed to respect the specific angle. The resin injection step...
Article
Full-text available
The CRTM technique (Compression Resin Transfer Moulding) is a derivative of the RTM process. Contrary to the RTM process, it enables the moulding of composite parts with a high content of fibers and a faster production rate. It is composed of a stage of injection of the resin and a stage of compression of the mould which can occur separately or sim...
Chapter
In this article, cost is defined and various components of cost to manufacture composite material products are presented. These components include material cost, labor cost, and tooling and capital cost. Factors constituting these components of cost are discussed in detail. Various costing methods being used in practice are introduced. Finally, it...
Article
Full-text available
The optimization of the couplings between LCM processes and structural performances by repeated numerical simulations is expensive in terms of the computational cost. In order to overcome this difficulty, we propose a semi-analytical modeling of RTM and CRTM processes. Various processing routes of CRTM are considered according to the combinations o...
Article
Full-text available
In recent years, a need for composite materials for primary structural applications has been continually increasing. Liquid composites moulding (LCM) processes such as the RTM (Resin Transfer Moulding) process, are used to manufacture high quality and complex-shaped fibre reinforced polymer composite parts particularly in the aeronautic industry. T...
Article
Full-text available
In this study, we performed three dimensional viscoelastic flow simulations with freely suspended platelet particles for the application of effective coloring of polymers. The model problem with a partial drag surface mimics a recently proposed design to remove typical platelet particle orientation near the weld line. A standard combination for the...
Conference Paper
Full-text available
Liquid composite molding (LCM) processes consist of injecting a liquid resin through a fibrous reinforcement. In the resin transfer molding (RTM) process, liquid thermosetting resin is injected under pressure into a rigid mold filled with fiber perform. In resin infusion processes (such as the vacuum assisted process), however, the preform stack is...