Publications associées à Fatigue behavior of transverse attachments under constant and variable amplitude loading from a Swiss motorway bridge

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

Single-Well Pore Pressure Preconditioning for Enhanced Geothermal System Stimulation

Marie Estelle Solange Violay, Barnaby Padraig Fryer, Mathias Alexandre David Lebihain

The stress state is an important parameter in terms of both earthquake nucleation and rupture. Here, a new stimulation technique is proposed for Enhanced Geothermal Systems (EGSs), which have previously been burdened with a number of high-profile incidence ...

2023

Psychosomatic response to acute emotional stress in healthy students

Adriana Arza Valdes

The multidimensionality of the stress response has shown the complexity of this phenomenon and therefore the impossibility of finding a unique biomarker among the physiological variables related to stress. An experimental study was designed and performed t ...

FRONTIERS MEDIA SA2023

Three-dimensional stress state during dynamic shear rupture propagation along frictional interfaces in elastic plates

Jean-François Molinari, Roozbeh Rezakhani

The state of stress in plates, where one geometric dimensions is much smaller than the others, is often assumed to be of plane stress. This assumption is justified by the fact that the out-of-plane stress components are zero on the free-surfaces of a plate ...

ELSEVIER2022

Fatigue of reinforced UHPFRC members and monitoring of fatigue action effects on bridges

Bartlomiej Wojciech Sawicki

The objective of this thesis is to develop knowledge and methods to prevent fatigue failure of bridges. The Fatigue Limit State is investigated from both the demand (S) and resistance (R) side. The S-part focuses on reduction of uncertainties through monit ...

EPFL2021

Role of mean stress on fatigue behavior of a 316L austenitic stainless steel in LWR and air environments

Philippe Spätig, Hans-Peter Seifert

Mean stress effects on fatigue life of a stainless steel in air and boiling water reactor (BWR) environments were evaluated by load-controlled tests. In stress-life, non-zero mean stresses increase life in low cycle fatigue regime in both environments and ...

ELSEVIER SCI LTD2021

Fatigue resistance of reinforced UHPFRC beams

Eugen Brühwiler, Bartlomiej Wojciech Sawicki

This work investigates the fatigue resistance of reinforced Ultra High Performance Fiber Reinforced Cementitious composite (R-UHPFRC) beams with special consideration of steel rebar – UHPFRC interaction under tensile stresses due to bending. Experimental t ...

2021

Multiaxial fatigue criteria for prestressed strengthening of steel connections

Alain Nussbaumer, Elyas Ghafoori, Masoud Motavalli, Hossein Heydarinouri

In this study, the high-cycle fatigue behavior of bridge connections subjected to distortion-induced loadings (generating multiaxial stresses) and strengthened with prestressed elements were experimentally investigated. Thereafter, appropriate critical pla ...

ELSEVIER SCI LTD2021

The influence of the kinematics of rough surface engagement on the transfer of forces in cracked concrete

Miguel Fernández Ruiz

One of the most instrumental aspects governing the response of structural concrete at ultimate limit state refers to the possibility of developing smeared cracking patterns within a member (associated normally to the presence of sufficient reinforcement fo ...

2021

Effective stress for unsaturated active clays and in-situ effective stress estimation methodology

Angelica Tuttolomondo

The complexity of the mechanics of active clays and, more generally, of geomaterials with clay minerals, under saturated and unsaturated conditions, still provides relevant scientific challenges today. Equally relevant challenges are the understanding of t ...

EPFL2021

Multiaxial fatigue analysis of high-strength steel welded joints using generalized local approaches

Martin Antonio René Garcia

The objective of this thesis is to improve methods for predicting the fatigue life, multiaxial or not, of mild- and more particularly high-strength steels using local approaches that have the capacity to be applicable to almost any cases, hence the term ge ...

EPFL2020

Experimental evaluation and modeling of fatigue of a 316L austenitic stainless steel in high-temperature water and air environments

Wen Chen

Austenitic stainless steels is used in many components of nuclear power plants, particularly in the pipes of cooling systems. Owing to power transients and to start-ups and shutdowns, these components are subjected to thermo-mechanical loadings (low-cycle ...

EPFL2020

Stress management in the context of induced seismicity in subsurface reservoirs

Barnaby Padraig Fryer

The stress state of the subsurface has been shown to have an influence on a number of key processes. For example, the criticality of the stress state indicates how large stress changes need to be before a fault begins to slip, the mean effective stress con ...

EPFL2020

Static and Fatigue Biaxial Flexural Behavior of Strain-Hardening UHPFRC Thin Slab Elements

Xiujiang Shen

Cast-in-place thin layers of Ultra-High Performance Fiber Reinforced Cementitious Composites (UHPFRC) on the specific zones of existing reinforced concrete (RC) bridge decks has been demonstrated to be a technically efficient and economic rehabilitation an ...

EPFL2020

Investigation of the effect of Laser Shock Peening in Additively Manufactured samples through Bragg Edge Neutron Imaging

Roland Logé, Nikola Kalentics, Markus Strobl

Additive manufacturing is a promising and rapidly rising technology in metal processing. However, besides a number of key advantages the constitution of a part through a complex thermo-mechanical process implies also some severe issues with the potential o ...

ELSEVIER2020

Locomotion in virtual environments predicts cardiovascular responsiveness to subsequent stressful challenges

Maria del Carmen Sandi Perez, Nathalie Heidi Meyer, João Pedro de Matos Rodrigues, Stephan Streuber, Erik Hans Jakob Studer

Individuals differ in their physiological responsiveness to stressful challenges, and stress potentiates the development of many diseases. Heart rate variability (HRV), a measure of cardiac vagal break, is emerging as a strong index of physiological stress ...

Nature Research2020

Hydraulic Transport Through Calcite Bearing Faults With Customized Roughness: Effects of Normal and Shear Loading

Marie Estelle Solange Violay, Mateo Alejandro Acosta

Understanding fluid flow in rough fractures is of high importance to large scale geologic processes and to most anthropogenic geo‐energy activities. Here we conducted fluid transport experiments on Carrara marble fractures with a novel customized surface t ...

2020

Load history effects in fibre-reinforced polymer composite materials

Abdolvahid Movahedirad

Today, it is widely accepted that fatigue is one of the most common failure mechanisms in structural components, and pure static failure is rarely observed. Engineering structures are subjected to complex mechanical fatigue loading histories, which cause d ...

EPFL2019

Stress ratio effect on tension-tension fatigue behavior of angle-ply GFRP laminates

Thomas Keller, Anastasios Vassilopoulos

The effect of the stress ratio (R = sigma(min)/sigma(max)) on the fatigue behavior of (+/- 45)(2s) angle-ply glass/epoxy composite laminates was investigated by comparing their mechanical, thermal, and optical properties under the stress ratio of 0.5 with ...

2019

Modeling of fatigue behavior based on interaction between time- and cyclic-dependent mechanical properties

Thomas Keller, Anastasios Vassilopoulos

A general constitutive equation was established using the theory of viscoelasticity in order to consider the interaction of the time- and cyclic-dependent mechanical properties of laminated composites. This equation was solved for two specific loading patt ...

2019