Publications associées à Intralaminar fracture of unidirectional carbon/epoxy composite: experimental results and numerical analysis

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

An adaptive phase field approach to 3D internal crack growth in rocks

Tao Xu, Michael Heap, Alexandra Roma Larisa Kushnir

Modeling the 3D internal crack under compression entails complex fracture mechanics (mode I-II-III fracture), resulting in substantial computational costs and challenges in characterizing fracture morphology characterization for Phase Field Method (PFM) si ...

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

Quench Detection and Temperature Measurement With Fiber Optic Sensors

Davide Uglietti, Kamil Sedlák, Christoph Müller

For the EU DEMO conductor testing, a temperature sensor based on Fiber Bragg Grating (FBG) optical fiber is studied at the EPFL Swiss Plasma Center. The SULTAN test facility has been upgraded to use fiber optic sensor for temperature monitoring and quench ...

IEEE Institute of Electrical and Electronics Engineers2024

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

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

Controlling crystal cleavage in focused ion beam shaped specimens for surface spectroscopy

Philip Johannes Walter Moll, Matthias Carsten Putzke, Andrew Scott Hunter

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy. Both require atomicall ...

Aip Publishing2024

Influence of fiber orientation on the tensile behavior of UHPFRC and reinforced UHPFRC under static and fatigue loadings

Jian Zhan

Ultra-high performance fiber reinforced cementitious composite (UHPFRC) is a modern class of cementitious building materials. Because of its superior mechanical properties and durability, it is increasingly used globally to rehabilitate, strengthen and mod ...

EPFL2024

Dataset for "Complexity of crack front geometry enhances toughness of brittle solids"

John Martin Kolinski, Chenzhuo Li, Xinyue Wei

This data package supports the publication 'Complexity of crack front geometry enhances toughness of brittle solids' by Xinyue Wei, Chenzhuo Li, Cían McCarthy, and John M. Kolinski Nature physics (2024) - https://doi.org/10.1038/s41567-024-02435-x DOI: 1 ...

Zenodo2024

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

Experimental and analytical investigation of shear-reinforced concrete and dowel action

Marko Pejatovic

Codes of practice can be overly conservative, particularly for the shear resistance of reinforced concrete beams with shear reinforcement when large loads act close to supports. This thesis addresses the topic by proposing a refined design approach based o ...

EPFL2024

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

Experimental investigation of dowel action in reinforcing bars using refined measurements

Aurelio Muttoni, Marko Pejatovic

In typical reinforced concrete design, reinforcement is designed to carry axial forces, but it can also resist transversal forces by dowel action. This is usually neglected for simplicity's sake in the design phase, but it can be accounted for either expli ...

Ernst & Sohn2024

Additive Manufacturing of Bioinspired Mineral-Based Composites

Ran Zhao

Biominerals are used by natural organisms for example as structural supports and optical sensors. They are produced from a limited number of elements and under ambient conditions. Nevertheless, they often possess excellent mechanical properties and sometim ...

EPFL2024

Estimation of the bar stress based on crack width measurements in reinforced concrete structures

Aurelio Muttoni, Enrique Corres Sojo

Estimating the stress of reinforcing bars and its variations in service conditions can be useful to determine the reserve capacity of structures or to assess the risk of fatigue in the reinforcement. This paper investigates the use crack width measurements ...

Ernst & Sohn2024

Mode I fracture of thick adhesively bonded GFRP composite joints for wind turbine rotor blades

Véronique Michaud, Anastasios Vassilopoulos, Jialiang Fan

This article investigates the effects of voids, joint geometry, and test conditions on the quasi-static Mode I fracture performance of thick adhesive Double Cantilever Beam (DCB) joints such as those prevailing in wind industry and shipbuilding. The specim ...

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

Water weakening and the compressive brittle strength of carbonates: Influence of fracture toughness and static friction

Marie Estelle Solange Violay, Barnaby Padraig Fryer, Corentin Jean-Marie Rémi Noël

Water is ubiquitous within the pore space of rocks and has been shown to affect their physical and mechanical behaviour. Indeed, water can act on the rock strength via mechanical (i.e., reducing the effective stresses) or chemical effects (e.g., mineral di ...

2024

Influence of model uncertainty and long term deformations in action effects calculation in reinforced concrete structures

Xhemsi Malja

Most codes of practice adopt a semi probabilistic design approach for the dimensioning and assessment of structures. Accordingly, structural safety is ensured by performing limit state verifications using design values determined with adequately calibrated ...

EPFL2024