Publications related to Variations on R-curves and traction-separation relations in DCB specimens loaded under end opening forces or pure moments

Self-catalysed frontal polymerisation enables fast and low-energy processing of fibre reinforced polymer composites

Véronique Michaud, Baris Çaglar, Jacobus Gerardus Rudolph Staal

Frontal polymerisation has the potential to bring unprecedented reductions in energy demand and process time to produce fibre reinforced polymer composites. Production of epoxy-based fibre reinforced polymer parts with high fibre volume content, commonly e ...

2024

Shear and steel-fibre reinforcement for the punching resistance of flat slabs at internal and edge columns

Diego Hernández Fraile

Reinforced concrete flat slabs consist of a continuous, thin concrete plate that rests on a grid of columns. The supporting surface of the columns is very small compared to the floor plan dimensions, leading to concentrations of shear forces near the colum ...

EPFL2024

Novel multi-crack damage approach for pultruded fiber-polymer web-flange junctions

Thomas Keller

This paper aims to propose a novel approach to assess the multi-crack behavior of layered fiber-polymer composites. The Compliance and R-curves generated from this novel approach were useful to understand the multiple delamination process, enabling to eval ...

Elsevier Sci Ltd2023

New SIDH Countermeasures for a More Efficient Key Exchange

Andrea Basso, Tako Boris Fouotsa

The Supersingular Isogeny Diffie-Hellman (SIDH) protocol has been the main and most efficient isogeny-based encryption protocol, until a series of breakthroughs led to a polynomial-time key-recovery attack. While some countermeasures have been proposed, th ...

Springer2023

Strategies for energy-efficient frontal polymerisation processing and microstructural evaluation of fibre reinforced composites

Jacobus Gerardus Rudolph Staal

Liquid composite moulding methods are widely applied for manufacturing of fibre reinforced polymer (FRP) composites and consist of two main stages: impregnation of fibrous reinforcements by a liquid monomer resin and curing of this resin. This thesis work ...

EPFL2023

Incorporation of Lignin in Bio-Based Resins for Potential Application in Fiber-Polymer Composites

Mário Alexandre De Jesus Garrido, Mateus De Assunção Hofmann

Bio-based resins, obtained from renewable raw materials, are a more sustainable alternative to oil-based resins for fiber-reinforced polymer (FRP) composites. The incorporation of lignin in those resins has the potential to enhance their performance. This ...

MDPI2023

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

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

Capillary Effects in Fiber Reinforced Polymer Composite Processing: A Review

Véronique Michaud, Baris Çaglar, Jacobus Gerardus Rudolph Staal, Helena Luisa Teixido Pedarros

Capillarity plays a crucial role in many natural and engineered systems, ranging from nutrient delivery in plants to functional textiles for wear comfort or thermal heat pipes for heat dissipation. Unlike nano- or microfluidic systems with well-defined por ...

FRONTIERS MEDIA SA2022

A Novel Method to Quantify Self-Healing Capabilities of Fiber-Reinforced Polymers

Véronique Michaud, Amaël Maximilien Cohades, Robin Samuel Trigueira, Cecilia Scazzoli

The present work investigates a novel and practical method to evaluate the healing efficiency of carbon-reinforced polymer composites. The method should be representative of damage occurring during the lifetime of a composite part, should tend to damage th ...

FRONTIERS MEDIA SA2022

A life cycle analysis of novel lightweight composite processes: Reducing the environmental footprint of automotive structures

Véronique Michaud, Colin Gomez, Baris Çaglar, Vincent Werlen, Christian Rytka

In this study, three novel thermoplastic impregnation processes were analyzed towards automotive applications. The first process is thermoplastic compression resin transfer molding in which a glass fiber mat is impregnated in through thickness by a thermop ...

ELSEVIER SCI LTD2022

Probing the buckling of pressurized spherical shells

Pedro Miguel Nunes Pereira de Almeida Reis, Dong Yan, Arefeh Abbasi

The prediction of the critical buckling conditions of shell structures is plagued by imperfection sensitivity. Non-destructive testing through point-load probing has been recently proposed to map the stability landscape of cylindrical shells. However, the ...

2021

Monitoring of Torque Induced Strain in Composite Shafts with Embedded and Surface-Mounted Optical Fiber Bragg Gratings

John Botsis, Georgios Violakis, Georgios Pappas

In this study, silica glass, optical fiber Bragg gratings (FBGs) are used for torque-induced strain monitoring in carbon fiber reinforced polymer (CFRP) hollow shafts toward the development of a methodology for structural load monitoring. Optical fibers wi ...

2021

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

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

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

Micromechanical study on the origin of fiber bridging under interlaminar and intralaminar mode I failure

John Botsis, Georgios Pappas, Fernando Naya Montans

Fiber reinforced polymers (FRPs) subjected to mode I fracture show important toughening due to the development of large scale bridging (LSB). Experimental studies of this phenomenon in unidirectional carbon/epoxy laminates using double cantilever beam spec ...

ELSEVIER SCI LTD2019

Many touchings force many crossings

János Pach

Given n continuous open curves in the plane, we say that a pair is touching if they have finitely many interior points in common and at these points the first curve does not get from one side of the second curve to its other side. Otherwise, if the two cur ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2019

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

Assessment of capillary phenomena in liquid composite molding

Véronique Michaud, Baris Çaglar, Feyza Karasu Kiliç, Cem Tekin

The interplay between capillary and viscous forces plays a significant role for optimal part quality in fiber-reinforced composites manufactured by Liquid Composite Molding (LCM); these are however difficult to analyze during flow. Two approaches are propo ...

2019