Publications related to Plywood

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

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

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

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

Steel Sheet Sheathed Cold-Formed Steel Framed In-line Wall Systems. I: Impact of Structural Detailing

Fani Derveni

The North American construction industry has seen substantial growth in the use of cold-formed steel (CFS) framing for midrise buildings in recent years. In seismic zones, CFS-framed buildings utilize shear walls to provide the primary lateral resistance t ...

ASCE-AMER SOC CIVIL ENGINEERS2022

Mechanical properties of a balsa wood veneer structural sandwich core material

Thomas Keller, Anastasios Vassilopoulos, Niloufar Vahedi

Balsa wood is an appropriate core material for structural sandwich applications due to its high strength- and stiffness-to-weight ratios. However, the mechanical properties vary considerably owing to the inherent scattering of natural wood materials. One a ...

2020

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

Thermomechanical characterization of a balsa-wood-veneer structural sandwich core material at elevated temperatures

Thomas Keller, Anastasios Vassilopoulos, Chao Wu, Niloufar Vahedi

The tensile, compressive and shear behavior of standardized specimens cut from a veneered balsa wood used as structural sandwich core was investigated at ambient temperatures of up to 250 degrees C. The average moisture content was 9.1%. The specimens' res ...

ELSEVIER SCI LTD2020

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

John Botsis, Georgios Pappas, Charlie Joseph Simon Blondeau

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

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

John Botsis, Robin Amacher, Joël Cugnoni, Sébastien Kohler

Thin-ply composites were shown to exhibit significantly delayed transverse cracking, but the linear onset of damage scaling with ply thickness reported by Amacher et al. (2014) did not correspond to the established LEFM based in situ strength model. This s ...

2019

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

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

John Botsis, Georgios Pappas, Charlie Joseph Simon Blondeau

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

Influence of the stacking sequence on the low-energy impact resistance of flax/PA11 composite

Yann Albert Gérard Lebaupin

In this paper, the low-energy impact behavior of a fully biobased composite made of bio-sourced polyamide 11 resin reinforced with flax fibers was investigated. Different composite laminates were studied in order to determine the stacking sequence effects ...

SAGE PUBLICATIONS LTD2019

Towards aerospace grade thin-ply composites: Effect of ply thickness, fibre, matrix and interlayer toughening on strength and damage tolerance

John Botsis, Robin Amacher, Joël Cugnoni, Larissa Sorensen, Sébastien Kohler

Thin-ply composites represent a promising approach to further improve the performance of carbon fibre composite structures thanks to their ability to delay the onset of matrix cracking and delamination up to the point of fibre dominated failure. However, t ...

ELSEVIER SCI LTD2018

The influence of through-thickness reinforcement geometry and pattern on delamination of fiber-reinforced composites: Part I - Experimental results

Véronique Michaud, John Botsis, Georgios Pappas

This experimental study reports effect of tuft geometry i.e., standard tufts and loops milled-down, and tufting pattern on Mode I interlaminar fracture in a GFRP. Standard tufting geometry is responsible for an increase in fracture resistance by 3.5-6 time ...

Elsevier2018

Fracture of thin-ply composites : effects of ply thickness

Guillaume Frossard

The demand for carbon/epoxy laminated composites is continuously increasing due to their high specific modulus and strength. Among them, laminates made of particularly thin layers (from t=0.015 to 0.150 mm) and called thin-ply composites are gaining in int ...

EPFL2017

Integrally attached timber folded surface structures : geometrical, experimental and numerical study

Andrea Stitic

In structural engineering, folded surface structures present one of the concepts for construction of self supporting column free systems. They utilize structural benefits of folding to achieve material saving and improve structural efficiency. The folding ...

EPFL2017

An efficient method for fiber bridging traction identification based on the R-curve: Formulation and experimental validation

John Botsis, Joël Cugnoni, Thomas Gmür, Guillaume Frossard

Fiber bridging is one of the main toughening mechanisms in mode I interlaminar and intralaminar fracture of laminated composites. Intact fibers exert closing forces on both faces of the crack, restraining crack propagation. An effective identification proc ...

Elsevier2017

Effect of an adhesive layer on the mode I delamination in unidirectional CFRP bonded joints

Nassima Nasri

Several toughening mechanisms, such as fibre bridging, can occur during delamination of fibre reinforced composites. In structures made of composite bonded joints, delamination can occur either in the composite or in the adhesive layer. In the first case c ...

EPFL2017

Mode I interlaminar fracture of carbon epoxy laminates: Effects of ply thickness

John Botsis, Joël Cugnoni, Thomas Gmür, Guillaume Frossard

In this work, the influence of ply thickness on strain energy release rate (ERR) in delamination of carbon epoxy laminates is addressed. Specimens with three ply thicknesses: 0.030, 0.075 and 0.150 mm are tested. While the ERR at onset of crack propagation ...

Elsevier2016