Publications by Thomas Keller | EPFL Graph Search

Methodology for Calibrating Fatigue Load Models for Composite Road Bridges

Current fatigue load models (FLMs) for road bridges are typically calibrated based on steel and reinforced-concrete bridges. These models are not likely applicable to fiber–polymer composite bridges, primarily because the damage rate—defined as the slope o ...

2025

Composite engineering structures in seawater − Review of durability and environmental performance

Thomas Keller, Tara Habibi

Shoreline protection systems composed of fibre-polymer composite structures immersed in seawater may efficiently contribute to mitigate impacts of climate change, such as more frequent and severe coastal flooding and storm surges, and significant rises of ...

2025

Design of fibre-polymer composite structures: Commentary to European technical specification CEN/TS 19101: 2022

Thomas Keller

The European Technical Specification CEN/TS 19101:2022, "Design of Fibre-Polymer Composite Structures", constitutes a milestone for the use of fibre-polymer composites in civil engineering works. This book comprises around 400 background reports covering t ...

CRC Press2025

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

Overview and Aspects of the European Technical Specification CEN/TS 19101:2022, "design of Fibre-Polymer Composite Structures"

Thomas Keller

In November 2022, the European Committee for Standardization (CEN) published the Technical Specification CEN/TS 19101:2022, "Design of Fibre-Polymer Composite Structures."These design provisions, which follow the philosophy and partial factor format of the ...

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

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

Composites in Structural Engineering and Architecture

Thomas Keller

This monograph is about the author’s 25-year journey as a pioneer, scientist, designer, and lecturer in the field of fibre-polymer composites, applied to structural engineering and architecture. Composites are construction materials that offer unique prope ...

EPFL Press English Imprint2024

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

Thomas Keller, Landolf-Giosef-Anastasios Rhode-Barbarigos, Tara Habibi

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

Fire Dynamic Responses of Fiber-Reinforced Polymer Composite Buildings

Thomas Keller

Glass fiber-reinforced polymer (GFRP) composites have been used in civil construction because of their high strength, lightweight, and corrosion resistance. However, their thermal sensitivity due to the polymer resin requires further understanding of the f ...

Asce-Amer Soc Civil Engineers2024

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

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

Experimental investigation of two-dimensional Mode-II delamination in composite laminates

Thomas Keller, Anastasios Vassilopoulos, Congzhe Wang

The two-dimensional (2D) delamination growth in composite laminates under the Mode-II fracture condition was experimentally investigated using a novel set-up. Circular plate specimens with a centrally embedded pre-crack of two sizes were semi-clamped along ...

2023

Effects of core air gaps and steel inserts on thermomechanical response of GFRP-balsa sandwich panels subjected to fire

Thomas Keller, Anastasios Vassilopoulos, Niloufar Vahedi

Composite sandwich panels composed of a balsa core and glass fiber-reinforced polymer (GFRP) face sheets may offer attractive applications for building slabs and bridge decks. Such composite panels may contain air-filled gaps (caused by initial defects or ...

ELSEVIER SCI LTD2023

Mechanical behavior and failure of carbon fiber-reinforced composite sandwich structure inspired by curved-crease origami

Thomas Keller

Origami offers a novel design possibility for periodic sandwich cores. The curved-crease origami is adopted to enhance the anti-buckling performance and reduce the abrupt change of the carbon fibers in the origami sandwich cores. CFRP curved-crease origami ...

ELSEVIER SCI LTD2023

Effects of prestress implementation on self-stress state in large-scale tensegrity structure

Thomas Keller, Tara Habibi

Tensegrity structures are spatial, reticulated, and lightweight structures that are composed of struts and cables. Stability is provided by a self-stress state between tensioned and compressed members obtained by prestress. Although the form finding of ten ...

ELSEVIER SCI LTD2023

A novel methodology of predicting temperature and rate effects on tensile properties of viscoelastic materials

Thomas Keller

A novel methodology to predict the tensile properties of viscoelastic materials as a synergistic function of temperature and loading/displacement rate is presented in this paper. The model is based on the amount of energy dissipated during tensile loading, ...

Pergamon-Elsevier Science Ltd2023

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

Prefabricated thermally-activated fiber-polymer composite building slab P-TACS: Toward the multifunctional and pre-fabricated structural elements in buildings

Thomas Keller, Dolaana Khovalyg

The traditional sequential design of building elements, where every element performs only one dedicated function, carries significant embodied energy. Thus, modular pre-fabricated load-bearing elements could overcome the disadvantages of the current carbon ...

SAGE PUBLICATIONS LTD2023

Experimental and theoretical study on out-of-plane compression buckling properties of grid beetle elytron plate

Thomas Keller

Based on the shell and plate theory, this paper uses the divide-and-combine method (DCM) to derive an analytical out-of-plane compression buckling limit expression of the basic unit of the core layer of a grid beetle elytron plate (GBEP); the accuracy of e ...

SPRINGER2023