Publications by John Botsis | EPFL Graph Search

Related publications (113)

An experimental-numerical study of moisture absorption in an epoxy

John Botsis, Joël Cugnoni, Dragan Coric, Marco Lai

It is well known that moisture absorption impairs the mechanical and physical properties of polymers. Conventionally, the material's hygric strains are described as the product of a constant coefficient of moisture expansion (CME) and moisture concentratio ...

2012

On the mechanical characteristics of a self-setting calcium phosphate cement

John Botsis, Luis Pablo Canal Casado

Objective: To perform a mechanical characterization of a self-setting calcium phosphate cement in function of the immersion time in Ringer solution. Materials and methods: Specimens of self-setting calcium phosphate cement were prepared from pure alpha-TCP ...

Elsevier2017

Three-dimensional morphometry of strained bovine periodontal ligament using synchrotron radiation-based tomography

John Botsis, Joël Cugnoni, Marzio Bergomi

The periodontal ligament (PDL) is a highly vascularized soft connective tissue. Previous studies suggest that the viscous component of the mechanical response may be explained by the deformation-induced collapse and expansion of internal voids (i.e. chiefl ...

2010

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

John Botsis, Georgios Pappas

Fracture of carbon fiber reinforced polymers (CFRPs) is dominated by large scale fiber bridging which acts as a very important toughening mechanism. The objective of this paper is to investigate the intralaminar Mode I fracture in a unidirectional CFRP com ...

Elsevier2016

Experimental and numerical studies on size and constraining effects in lead-free solder joints

John Botsis, Joël Cugnoni

Search String Advanced > Saved Searches > ARTICLE TOOLS Get PDF (641K) Save to My Profile E-mail Link to this Article Export Citation for this Article Get Citation Alerts Request Permissions More Sharing ServicesShare | Share on citeuli ...

2007

An experimental-numerical investigation of hydrothermal response in adhesively bonded composite structures

Véronique Michaud, Hans Georg Limberger, John Botsis, Georgios Violakis, Roohollah Sarfaraz Khabbaz, Luis Pablo Canal Casado

Water absorption and thermal response of adhesive composite joints were investigated by measurements and numerical simulations. Water diffusivity, saturation, swelling, and thermal expansion of the constituent materials and the joint were obtained from gra ...

Elsevier2015

On the Mutual Effect of Viscoplasticity and Interfacial Damage Progression in Interfacial Fracture of Lead-Free Solder Joints

John Botsis, Joël Cugnoni, Milad Maleki

The main goal of this paper is to shed light on the effect of strain rate and viscoplastic deformation of bulk solder on the interfacial failure of lead-free solder joints. For this purpose, interfacial damage evolution and mode I fracture behavior of the ...

Springer US2011

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

John Botsis, Georgios Pappas, Charlie Joseph Simon Blondeau

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

Vibration-based characterization of impact induced delamination in composite plates using embedded FBG sensors and numerical modelling

John Botsis, Joël Cugnoni, Jeannot Frieden

Dynamic strain signals from embedded fiber Bragg grating sensors are used for experimental modal analysis in carbon fiber reinforced polymer plates. Throughout a series of impact tests, the change of eigen-frequencies due to damage is evaluated for differe ...

2011

An axisymmetric stress analysis in a single fibre composite of finite length under a thermal expansion mismatch

John Botsis, Laurent Humbert, Fabiano Colpo

In this paper, an exact solution is derived for the characterization of thermal stresses in a single-fibre composite of finite length. All the required boundary and interfacial conditions of the thermo-elastic problem are thus satisfied exactly. The propos ...

2009

Large scale fiber bridging in mode I intralaminar fracture. An embedded cell approach

John Botsis, Georgios Pappas, Luis Pablo Canal Casado

Fiber reinforced composites can develop large scale bridging upon mode I fracture. This toughening mechanism depends on the constituents and the geometry of the specimen, and is especially important in unidirectional laminates when fracture is parallel to ...

Elsevier2016

Crack - fiber sensor interaction and characterization of the bridging tractions in mode I delamination

John Botsis, Joël Cugnoni, Samuel Stutz

Fiber bridging is regularly encountered in model delamination tests of unidirectional fiber reinforced composites. However, characterization of the bridging tractions is rather difficult. One way to indirectly evaluate the bridging traction distribution is ...

2011

Improving delamination resistance through tailored defects

John Botsis, Niels Pichler

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

Microstructure-based modeling of the ageing effect on the deformation behavior of the eutectic micro-constituent in SnAgCu lead-free solder

John Botsis, Joël Cugnoni, Milad Maleki

The eutectic micro-constituent in SnAgCu solder governs the deformation behavior of the joint as it shows better deformation resistance than the Sn dendrites and occupies a high volume percentage of the whole solder. The main scope of this study is to deve ...

Elsevier2013

Mixed-mode fracture response of anti-symmetric laminates: Experiments and modelling

John Botsis, Niels Pichler

Multidirectional laminates are very often used in advanced structures. However, the existing data in the literature regarding their fracture response is not conclusive. In this work, the fracture response of a +45 degrees// -45 degrees interface is investi ...

ELSEVIER SCI LTD2020

Characterization of the Residual Stresses and Strength of Ceramic-Metal Braze Joints

John Botsis, Matteo Galli

Residual stress relief in ceramic-metal joints produced by active brazing depends primarily on the plastic response of the filler metal. A procedure for the production and mechanical characterization of bulk active filler alloy specimens is developed. In p ...

2009

Hydro-mechanical coupling in the periodontal ligament: A porohyperelastic finite element model

John Botsis, Joël Cugnoni, Matteo Galli, Marzio Bergomi

Harmonic tension–compression tests at 0.1, 0.5 and 1 Hz on hydrated bovine periodontal ligament (PDL) were numerically simulated. The process was modeled by finite elements (FE) within the framework of poromechanics, with the objective of isolating the con ...

Elsevier2011

Low energy impact damage monitoring of composites using dynamic strain signals from FBG sensors - Part I: Impact detection and localization

John Botsis, Thomas Gmür, Joël Cugnoni, Jeannot Frieden

Fiber reinforced composite materials risk to suffer from subsurface, barely visible, damage induced by transverse relatively low energy impacts. This two-paper series presents a method for the localization of an impact and identification of an eventual dam ...

2012

Stress and failure analysis of crimped metal-composite joints used in electrical insulators subjected to bending

John Botsis, Thomas Gmür, Alain Michel Prenleloup

Experimental and numerical investigations are carried out on metal/fibregiass-reinforced-plastic joints integrated in electrical insulators subject to bending. Numerical stress and strain distributions through the bond are calculated with a solid 3D finite ...

2009

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