Micro-CT-based analysis of fibre-reinforced composites:Applications

The paper presents an overview of cases in which the analysis of the internal structure and mechanical properties of fibre reinforced composites is performed based on the micro-computed X-ray tomography (micro-CT) reconstruction of the composite reinforcement geometry. In all the cases, the analysis relies on structure tensor-based algorithms for quantification of the micro-CT image, implemented in VoxTex software

Towards quantum 3d imaging devices

We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed

Non-linear material modeling of fiber-reinforced polymers based on coupled viscoelasticity–viscoplasticity with anisotropic continuous damage mechanics

International audienc

ラット高眼圧実験モデル網膜における網膜神経節細胞数の変化及びbcl-2, bax mRNA発現量の変化

International audienc

Fast Fourier transform solver for damage modeling of composite materials

International audienc

Meso-FE modelling of textile composites and X-ray tomography

International audienceAmong 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 and permeability) and performance in-service (response to applied loads and strains, including damage development). X-ray tomography (lCT) is a tool well suited for determining the 3D internal geometry of the composite. The current characteristics of the lCT devices allow micrometrescale characterization, providing high-quality geometrical models. The paper presents an overview of lCT-based meso-modelling of textile composites, illustrated by novel modelling results. It covers two segmentation methods (structural tensor and texture analysis), models of the behaviour (deformation response) at meso-scale of textile reinforcements and damage models for textile composites. A set of cases is analysed where X-ray tomography provides the definition of the initial models and the validation of the results obtained by mesoscopic analysis

Damage behavior of multilayer axisymmetric shells obtained by the FDM method

This research rigorously explores the additive synthesis of structural components, focusing on unraveling the challenges and defect mechanisms intrinsic to the fused deposition modeling (FDM) process. Leveraging a comprehensive literature review and employing theoretical modeling and finite element analysis using ANSYS software, the study meticulously investigates the behavior of multilayer axisymmetric shells under varying internal pressure conditions. Critical parameters are identified, and the impact of design factors, including material properties, geometric parameters, and internal pressure, is quantitatively assessed using a rich digital dataset. In a series of model experiments, the study reveals specific numerical results that underscore the progressive nature of damage development in FDM-produced multilayer axisymmetric shells. Notably, under increasing internal pressure, stresses on the tank’s inner walls reach up to 27.5 MPa, emphasizing the critical importance of considering material properties in the design phase. The research also uncovers that the thickness of tank walls, while significant in resulting stresses, does not markedly impact the damage development mechanism. However, it places a premium on selecting rational parameters for the honeycomb system, including shell thickness, honeycomb height, honeycomb wall thickness, and honeycomb cell size, to minimize stress concentrations and enhance structural integrity. The inclusion of honeycomb structures in the tank design, as evidenced by specific results, provides enhanced thermal insulation properties. The research demonstrates that this design feature helps localize damage and mitigates the formation of significant trunk cracks, particularly along generative cracks

Damage Behavior of Multilayer Axisymmetric Shells Obtained by the FDM Method

This research rigorously explores the additive synthesis of structural components, focusing on unraveling the challenges and defect mechanisms intrinsic to the fused deposition modeling (FDM) process. Leveraging a comprehensive literature review and employing theoretical modeling and finite element analysis using ANSYS software, the study meticulously investigates the behavior of multilayer axisymmetric shells under varying internal pressure conditions. Critical parameters are identified, and the impact of design factors, including material properties, geometric parameters, and internal pressure, is quantitatively assessed using a rich digital dataset. In a series of model experiments, the study reveals specific numerical results that underscore the progressive nature of damage development in FDM-produced multilayer axisymmetric shells. Notably, under increasing internal pressure, stresses on the tank’s inner walls reach up to 27.5 MPa, emphasizing the critical importance of considering material properties in the design phase. The research also uncovers that the thickness of tank walls, while significant in resulting stresses, does not markedly impact the damage development mechanism. However, it places a premium on selecting rational parameters for the honeycomb system, including shell thickness, honeycomb height, honeycomb wall thickness, and honeycomb cell size, to minimize stress concentrations and enhance structural integrity. The inclusion of honeycomb structures in the tank design, as evidenced by specific results, provides enhanced thermal insulation properties. The research demonstrates that this design feature helps localize damage and mitigates the formation of significant trunk cracks, particularly along generative cracks

Quantitative comparison between fast fourier transform and finite element method for micromechanical modeling of composite

International audienceA variety of numerical methods can be applied for multi-scale simulation of composite materials in general and textile reinforced composites in particular. Among numerical methods, the Finite Element Method (FEM) is the main tool for modeling textile composites [1]. Recent developments have brought increased interest in the Fast Fourier Transform (FFT) based method for multi-scale material modeling. This method uses image-based techniques and also gives accurate results as FEM voxel-based models do [2]. Backing to 1994, the FFT method was proposed initially by P.Suquet and H.Moulinec [3], as a voxel-based methodology that does not need stiffness matrix assembling like FEM. It can thus be very efficient in the field of digital materials and easily parallelized. The main drawback of voxel-based models is the presence of strong oscillations due to the non-smooth interface [4]. From the best of our knowledge, the FFT and FEM are often compared in a general way. In this work, specific problems of the micromechanics of composite materials were addressed in order to compare quantitatively FFT and FEM solutions of the stress field at the interface, based on the direct output and with the introduction of a smoothing method. The open-source software AMITEX [5] is applied for all FFT calculations and ABAQUS is applied for all FEM calculations