Publications related to Experimental investigation of the effect of the mould thermal expansion on the development of internal stresses during carbon fibre composite processing

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

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

Congzhe Wang

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

On the influence of flow-front orientation on stringer stiffened composite panels in water impacts

Véronique Michaud

Water impacts form the critical load case for high-performance carbon fibre reinforced polymer (CFRP) racing craft. Such events produce a peaked, non-uniform pressure distribution that travels along a hull panel as it is immersed. Current design standards ...

2024

Highly anisotropic carbon fiber electrodes for DEAs and their dynamic non-monotonic conductive properties

Yves Perriard, Stefania Maria Aliki Konstantinidi, Markus Koenigsdorff

A common method for creating compliant electrodes for dielectric elastomer actuators (DEAs) and soft sensors is to incorporate electrically conductive carbon particles into a polymer matrix. However, using unidirectional aligned carbon fibers instead not o ...

Society of Photo-Optical Instrumentation Engineers (SPIE)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

Investigation of mycelium film as the adhesive for poplar veneer bonding: insight into interfacial bonding mechanisms

Wenjing Sun

The emergence of mycelium-bonded biocomposites has been stimulated in the quest for sustainable development. These biocomposites exhibit enhanced mechanical properties through hot pressing, with mycelium playing a crucial role as both the adhesive and rein ...

Taylor & Francis Ltd2024

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

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

A novel fatigue life prediction methodology based on energy dissipation in viscoelastic materials, synergistic effects of stress level, stress ratio, and temperature

Thomas Keller, Abdolvahid Movahedirad, Lulu Liu

This work introduces a new methodology to predict the fatigue life of viscoelastic materials by considering the creep effect on fatigue behavior under the concurrent effects of stress level, stress ratio, and temperature. The model established based on the ...

2024

Strain engineering and strain measurement by spring tethers on suspended epitaxial GaN-on-Si photonic crystal devices

Romuald Houdré, Jun Wang

Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, des ...

Iop Publishing 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

The Development of Aptamer-Coupled Microelectrode Fiber Sensors (apta-?FS) for Highly Selective Neurochemical Sensing

Fabien Sorin

The selective and sensitive sensing of neurochemicals is essential to decipher in-brain chemistry underlying brain pathophysiology. The recent development of flexible and multifunctional polymer-based fibers has been shown useful in recording and modulatin ...

AMER CHEMICAL SOC2023

Energy dissipation in fiber-polymer composites adhesive joints under cyclic loading

Ghazaleh Eslami

Sustainable development has emerged as a paramount consideration in various fields of industry, including construction, to preserve the environment and its finite resources. Lightweight structures, such as fiber-polymer composite structures, address both s ...

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

Experimental investigation of rotational behavior of pseudo-ductile adhesive angle joints exhibiting variable strain rate

Thomas Keller, Abdolvahid Movahedirad, Ghazaleh Eslami

Pseudo-ductile behavior in composite structural frames can be achieved by enabling their beam-column joints to exhibit nonlinear structural response due to progressive damage, by using pseudo-ductile adhesives. This study investigates the static behavior o ...

2023

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

Influence of Fiber Orientation on the Elastic Limit Tensile Stress of UHPFRC

Eugen Brühwiler, Emmanuel Denarié, Jian Zhan

The elastic limit tensile stress of UHPFRC is governed by contributions of the cementitious matrix and the fibrous skeleton. This paper finds that fiber orientation has significant influence on the matrix tensile strength of UHPFRC, while this is not consi ...

2023

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

Visualization and modelling of dynamic flow in fibrous preforms for liquid composite molding

Helena Luisa Teixido Pedarros

Nowadays, Liquid Composite Molding techniques are often used to manufacture high quality fiber reinforced composite parts at a relatively low cost. These involve an infiltration process, in which a liquid resin is forced to ingress into a dry fibrous porou ...

EPFL2023