Publications related to Experimental investigation of the fatigue behavior of adhesively-bonded pultruded GFRP joints under different load ratios

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

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

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

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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

Short-term behavior of glass fiber-polymer composite bending-active elastica beam under service load application

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Bending-active elastica beam is a structural configuration that is based on the elastic deformation of an initially straight beam. This deformation occurs when horizontal displacements are applied to a sliding support, causing the beam to bend into an arch ...

2024

Tension-tension fatigue behavior of basalt composite hybrid joints

Thomas Keller, Lulu Liu, Xin Wang

The tension–tension fatigue behavior of pseudo-ductile hybrid bonded-bolted double lap basalt composite joints, composed of pseudo-ductile adhesives and adherends with multi-directional fiber architecture, was experimentally investigated. The fatigue damag ...

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

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

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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

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

Encapsulation strategies for mechanical impact and damp heat reliability improvement of lightweight photovoltaic modules towards vehicle-integrated applications

Fabiana Lisco

Lightweight modules are essential for next-generation vehicle-integrated photovoltaic (VIPV) applications, such as solar-powered cars, allowing integration of solar cells beyond the roof, and on the hood, boot and body panels, and thereby extending the dri ...

Elsevier2024

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

Strain-based analysis on the influence of local undercut geometry on fatigue crack initiation life

Alain Nussbaumer, Heikki Tapani Remes, Abinab Niraula

The local undercut defects at the weld toe provide a potential initiation site for fatigue cracks and significantly impact the structure's fatigue strength. The influence of continuous undercut depth on fatigue performance is widely studied, but the resear ...

2024

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

Reliability analysis and partial safety format calibration considering the characteristics of the resistance of reinforced concrete structures

Qianhui Yu

Every engineering calculation is an approximation of reality, with inevitable uncertainties involved. This fact implies that a reliability verification accounting for the uncertainties is a necessary step in the design and assessment of structures. Nowaday ...

EPFL2023

CRACK SHIELDING MECHANISMS OF INTERLAYERED EPOXY MATERIALS UNDER QUASI-STATIC AND FATIGUE LOADING

Anastasios Vassilopoulos, Dharun Vadugappatty Srinivasan

This research explores the capability of PEI and PVDF thermoplastic interlayers to arrest cracks in epoxy materials modified with short-glass fibers and core-shell rubber particles. It also investigates the effect of interlayer position, the number of inte ...

Queen's University Belfast2023

Effect of fiber architecture on tension-tension fatigue behavior of bolted basalt composite joints

Thomas Keller, Lulu Liu, Xin Wang

The effect of fiber architecture, i.e., unidirectional (UD) vs. multi-directional (MD), on the tension-tension fa-tigue behavior of bolted double-lap basalt composite joints was experimentally investigated. The fatigue load-life (F -N) curves of MD and UD ...

ELSEVIER SCI LTD2023

Fatigue behavior and life prediction of wind turbine blade composite materials

Anastasios Vassilopoulos

Fatigue life prediction of wind turbine rotor blades is a very challenging task, as their failure is led by different failure types that act synergistically. Inherent defects like wrinkles, fiber misalignments, and voids that can be introduced during fabri ...

Woodhead Publishing (Elsevier)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

Exploring the potential of the critical shear crack theory for reinforced and post-tensioned glass beams: Initial analysis and experiments

Alain Nussbaumer, Pieter Christian Louter, Jagoda Cupac

In the evolution of structural glass beam elements, the requirements for post-fracture load bearing capacity and safe failure behaviour have led to the development of reinforced and post-tensioned beams. Maximum bending capacity in the post-fracture state ...

2023

Mode I and Mode II fracture behavior in pultruded glass fiber-polymer - Experimental and numerical investigation

Thomas Keller

Many recent works have shown that the capacity of pultruded glass fiber-polymer structural members is governed by interlaminar failure. However, there is still a lack of information regarding the fracture properties associated and the best techniques to be ...

Elsevier Sci Ltd2023

Using video detection of snow surface movements to estimate weak layer crack propagation speeds

Bertil Trottet, Johan Alexandre Philippe Gaume, Alec van Herwijnen

Dry-snow slab avalanches release due to crack propagation in a weak snow layer under a cohesive snow slab. Crack propagation speeds can provide insights into the potential size of avalanches and inform fracture and avalanche release models. Despite their i ...

CAMBRIDGE UNIV PRESS2023