Publications associées à Transverse cracking in the bulk and at the free edge of thin-ply composites: experiments and multiscale modelling

Two-dimensional quasi-static delamination in composite laminates under Mode-I and Mode-II conditions

Fiber-polymer composites consist of a polymer matrix and reinforcing fibers made of various materials. These composites exhibit exceptional properties, such as a high strength-to-weight ratio and excellent corrosion resistance, which has led to their incre ...

EPFL2024

Experimental characterization and stochastic models for time-dependent rupture of thin-ply composite laminates

Thin-laminate composites with thicknesses below 200 mu m hold significant promise for future, larger, and lighter deployable structures. This paper presents a study of the time-dependent failure behavior of thin carbon-fiber laminates under bending, focusi ...

2024

Numerical investigation of two-dimensional Mode-II delamination in composite laminates

Thomas Keller, Anastasios Vassilopoulos, Congzhe Wang

Existing standards for delamination tests on composite materials typically employ one-dimensional (1D) beam specimens. However, such specimens may not represent real delamination scenarios in composite structures, where cracks tend to propagate in two dime ...

Elsevier Sci Ltd2024

Multi-scale characterization and modeling of notched strength and translaminar fracture in hybrid thin-ply composites based on different carbon fiber grades

Guillaume Clément Broggi

Owing to their high specific stiffness and strength, Carbon Fiber Reinforced Composites (CFRP) are ideal candidates for the development of lightweight high-performance structures. Within this family, thin-ply composites allow for wider design freedom and p ...

EPFL2023

Process development of pre-impregnated hybrid thin-ply composites

Alexios Argyropoulos

Thin-ply composites, obtained with recently developed fiber spreading techniques, rapidly gained industrial interest because they offer a large composite design freedom, and lead to a composite tensile strength that is close to that of the individual fiber ...

EPFL2023

Semiconductor-based device architectures in multimaterial fibers

William Nicolas Duncan Esposito

Semiconductor materials have given rise to today's digital technology and consumer electronics. Widespread adoption is closely linked to the ability to process and integrate them in devices at scale. Where flexibility and large surfaces are required, such ...

EPFL2023

Cyclic Behaviour of Unidirectional Hybrid Interlayer Glass/Carbon and Carbon/Carbon Composites

Anastasios Vassilopoulos, José Manuel de Sena Cruz

The lack of ductility is a major drawback of fibre reinforced polymer (FRP) materials. As it is known, these materials are stiff and strong, but brittle with little or no warning before final failure. In the last decades, some solutions have been proposed ...

SPRINGER-VERLAG SINGAPORE PTE LTD2022

Thermally Drawn CNT-Based Hybrid Nanocomposite Fiber for Electrochemical Sensing

Inès Richard, Fabien Sorin

Nowadays, bioelectronic devices are evolving from rigid to flexible materials and substrates, among which thermally-drawn-fiber-based bioelectronics represent promising technologies thanks to their inherent flexibility and seamless integration of multi-fun ...

MDPI2022

Thermally-Drawn Multi-Electrode Fibers for Bipolar Electrochemistry and Magnified Electrochemical Imaging

Fabien Sorin

Imaging systems using closed bipolar electrode (cBPE) arrays and electrochemiluminescence (ECL) have attracted great attention in recent years as a 2D imaging platform with high spatiotemporal resolution. However, the fabrication techniques for cBPE arrays ...

Wiley2021

Crack propagation in CFRP laminates under mode I monotonic and fatigue loads: A methodological study

John Botsis, Charlie Joseph Simon Blondeau, Georgios Pappas

Delamination in composite materials is often accompanied by fiber bridging that increases resistance to crack growth. Here, delamination of two unidirectional carbon/epoxy systems was studied under monotonic and displacement-controlled fatigue loading. One ...

ELSEVIER SCI LTD2021

Soft functional fibers for mechanical sensing and actuation

Andreas Leber

The measurement and generation of mechanical deformations is a key functionality in health monitoring, human-machine interaction, and soft robotics. However, current methods typically rely on small and hard transducers, which result in poor performance, cu ...

EPFL2021

Improving delamination resistance through tailored defects

John Botsis

Delamination is a well-known damage mode exhibited by laminated composites which has been extensively studied in unidirectional laminates (UD). In this work, a novel strategy consisting of the introduction of a small interlaminar defect to enhance the frac ...

2020

Experiments and numerical modelling on angle-ply laminates under remote mode II loading

John Botsis, Charlie Joseph Simon Blondeau, Georgios Pappas

Delamination is a very frequent damage mechanism that affects the integrity of laminated composites. In this study, the effect of ply orientation on crack growth resistance was analyzed for three different anti-symmetric interfaces (+/- 30 degrees, +/- 45 ...

ELSEVIER SCI LTD2020

Mechanical properties of natural fiber composites produced using dynamic sheet former

Composites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic ...

2020

Centimeter-scale gas-sieving nanoporous single-layer graphene membrane

Luc Sébastien Bondaz, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Wan-Chi Lee

High-permeance, molecular-sieving, nanoporous single-layer graphene (NSLG) membranes are highly promising for gas separation. However, the formation of cracks during the transfer of NSLG to a low-cost porous support is difficult to avoid. These cracks are ...

2020

A comparative study of mode I delamination behavior of unidirectional glass fiber-reinforced polymers with epoxy and polyurethane matrices using two methods

John Botsis, Georgios Pappas

The mode I delamination behavior of a unidirectional glass-fiber reinforced polymer with a prototype elasto-plastic polyurethane matrix (GF/PU) was investigated and compared with that of glass/epoxy (GF/EP) using double cantilever beam specimens. Fracture ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Multiscale experimental characterisation and modelling of transverse cracking in thin-ply composites

Sébastien Kohler

In this work, the damage dependency on ply thickness is investigated experimentally for three different thin-ply CFRP quasi-isotropic laminates, with constituents spanning a large range of properties. It is shown that free edge damage mechanisms, observed ...

EPFL2019

Thermal Drawing of Polymer Nano-composites: Fluid Dynamic Analysis and Application to Novel Functional Fibers

Alexis Gérald Page

The thermal drawing process is emerging as a versatile platform for the development of multimaterial fiber devices and advanced textiles for sensing, energy harvesting or medical applications, owing to the possibility to integrate insulators, conductors an ...

EPFL2019

Influence of ply-angle on fracture in antisymmetric interfaces of CFRP laminates

John Botsis, Charlie Joseph Simon Blondeau, Georgios Pappas

Laminated composites are prone to fracture at layer interfaces. Such damage impairs their structural response and engenders important constraints in design. In this work, the influence of ply orientation on crack growth resistance was studied for three dif ...

ELSEVIER SCI LTD2019

Two-dimensional crack growth in FRP laminates and sandwich panels

Aida Cameselle Molares

Fiber-reinforced polymer (FRP) composite materials are currently being selected for the design of lightweight and efficient structural members in a wide number of engineering applications. Sandwich panels with glass fiber-reinforced polymer (GFRP) face she ...

EPFL2019