Recherche

Afficher tous les résultats pour

Accueil

Personne

Thomas Keller

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (309)

Modeling the constant amplitude fatigue behavior of adhesively bonded pultruded GFRP joints

Thomas Keller, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

The constant amplitude fatigue behavior of adhesively bonded pultruded glass fiber reinforced polymer double-lap joints were modeled by a number of conceptually different phenomenological SN (cyclic stress vs. number of cycle) formulations. An extended dat ...

Brill Academic Publishers2013

FRP-Balsa Composite Sandwich Bridge Deck with Complex Core Assembly

Julia De Castro San Roman Fest, Thomas Keller, Anastasios Vassilopoulos, Michael Osei-Antwi

The aim of this work was to investigate to what extent the performance of a glass fiber-reinforced polymer (GFRP) sandwich slab-bridge with a uniform high-density balsa core could be improved in terms of structural efficiency and weight by using a more com ...

American Society of Civil Engineers2013

Variable amplitude fatigue of adhesively-bonded pultruded GFRP joints

Thomas Keller, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

The fatigue behavior of adhesively-bonded pultruded GFRP joints subjected to variable amplitude loading patterns was experimentally investigated. The failure mode of the examined joints was found to be similar to that under constant amplitude loading. The ...

Elsevier Sci Ltd2013

Long-Term Development of Thermophysical and Mechanical Properties of Cold-Curing Structural Adhesives Due to Post-Curing

Julia De Castro San Roman Fest, Thomas Keller, Omar Moussa, Anastasios Vassilopoulos

The long-term changes in the thermophysical and mechanical properties of a cold-curing structural epoxy adhesive were investigated by accelerating the curing reaction by post-curing at elevated temperatures. Experimental data concerning the glass transitio ...

Wiley-Blackwell2013

Block loading fatigue of adhesively bonded pultruded GFRP joints

Thomas Keller, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

The effect of loading sequence on the fatigue behavior of adhesively-bonded pultruded GFRP double-lap joints was experimentally investigated by applying different tensile and compressive block loading patterns. The observed failure modes were consistent wi ...

2013

An analytical model for lateral contraction of composite laminates subjected to partially uniform tension

Julia De Castro San Roman Fest, Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

An analytical approach to determine the in-plane stress field and thereby the lateral contraction of composite rectangular plates subjected to partially uniform tension is presented. This approach is based on the Green function hypothesis and is able to ac ...

Pergamon-Elsevier Science Ltd2013

Pre-buckling and post-buckling failure at web-flange junction of pultruded GFRP beams

Thomas Keller, Yu Bai, Chao Wu

Separation at the web-flange junction is a common failure mode of pultruded glass fiber-reinforced (GFRP) beams subjected to bending. The causes of this separation appear to depend on the presence of lateral supports to prevent lateral buckling. To clarify ...

Springer Verlag2013

Punching shear of RC flat slabs - Review of analytical models for new and strengthening of existing slabs

Thomas Keller, Robert Koppitz

The conversion of existing buildings, development of standards, material deterioration and detailing deficiencies have led to a need for strengthening an increasing number of concrete flat slabs against brittle punching shear failure. However, existing ana ...

Elsevier2013

Ductility of civil engineering structures incorporating fibre reinforced polymers (FRPs)

Thomas Keller, Wendel Michael Sebastian

The special issue of the Construction and Building Materials journal has 14 papers covering a spectrum of studies from leading researchers the world over into the ductility characteristics of structural components or structures incorporating FRPs (fiber re ...

Elsevier2013

Shear mechanical characterization of balsa wood as core material of composite sandwich panels

Julia De Castro San Roman Fest, Thomas Keller, Anastasios Vassilopoulos, Michael Osei-Antwi

An experimental study was performed using Iosipescu specimens to evaluate the effects of parameters such as shear plane, density and adhesive joints on the shear stiffness and strength of balsa wood panels as well as the variation of ductility with respect ...

Elsevier2013

Modeling effects of asymmetry and fiber bridging on Mode I fracture behavior of bonded pultruded composite joints

Thomas Keller, Anastasios Vassilopoulos, Moslem Shahverdi

The fracture behavior of adhesively-bonded pultruded double cantilever beam specimens was experimentally investigated. The pultruded adherends comprised two mat layers on each side with a roving layer in the middle. An epoxy adhesive was used to form the d ...

Elsevier2013

Influences of polymer concrete surfacing and localised load distribution on behaviour up to failure of an orthotropic FRP bridge deck

Thomas Keller, Wendel Michael Sebastian

This paper presents experimental results which demonstrate the important, but to date little-studied influence of surfacing on the response up to failure of orthotropic GFRP bridge decking local to concentrated loading. Four bonded deck specimens were test ...

Elsevier2013

Experimental DSC-based method to determine glass transition temperature during curing of structural adhesives

Thomas Keller, Omar Moussa, Anastasios Vassilopoulos

A new DSC-based experimental method to efficiently establish the glass transition temperature, Tg, vs. curing degree, α, relationship for structural adhesives was developed. The method approaches the continuous Tg-α relationship with a trilinear curve esta ...

Elsevier2012

A hybrid S-N formulation for fatigue life modeling of composite materials and structures

Thomas Keller, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

A semi-empirical S-N formulation for the modeling of the constant amplitude fatigue behavior of composite materials and structures is introduced in this paper. The new S-N formulation is based on the commonly used exponential and power law fatigue models. ...

Elsevier2012

Experimental investigation and modeling of mean load effect on fatigue behavior of adhesively-bonded pultruded GFRP joints

Thomas Keller, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

The effect of mean load on the fatigue behavior of adhesively-bonded pultruded GFRP double-lap joints under constant amplitude loading was experimentally investigated. The joints were examined under nine different stress ratios (R) representing pure tensio ...

Elsevier2012

Experimental investigation of R-ratio effects on fatigue crack growth of adhesively-bonded pultruded GFRP DCB joints under CA loading

Thomas Keller, Anastasios Vassilopoulos, Moslem Shahverdi

A series of fatigue experiments was performed in order to investigate the effect of the R-ratio on the fatigue/fracture behavior of adhesively-bonded pultruded GFRP double cantilever beam joints. Constant amplitude fatigue experiments were carried out unde ...

Elsevier Sci Ltd2012

A total fatigue life model for the prediction of the R-ratio effects on fatigue crack growth of adhesively-bonded pultruded GFRP DCB joints

Thomas Keller, Anastasios Vassilopoulos, Moslem Shahverdi

A new phenomenological fatigue crack growth formulation for the modeling and the prediction of the Model fatigue behavior of adhesively-bonded pultruded glass fiber-reinforced polymer double cantilever beam joints under different R-ratios is introduced. Th ...

Elsevier2012

Load response due to local and global indeterminacies of FRP-deck bridges

Thomas Keller, Wendel Michael Sebastian

In a cellular FRP deck-on-beam bridge, the deck's load response is influenced by the cellular frame's local indeterminacy and by the global indeterminacy due to multiple beams at each support. Thus, the stiffness distributions for both levels of indetermin ...

2012

Modeling of Buckling and Wrinkling Behavior in GFRP Plate and Sandwiches Subjected to Biaxial Compression–Tension Loading

Julia De Castro San Roman Fest, Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

A model for predicting the buckling and wrinkling behavior of glass-fiber-reinforced polymer (GFRP) plates and sandwich panels subjected to in-plane biaxial compression-tension loading is presented in this paper. In-plane biaxial compression-tension loadin ...

American Society of Civil Engineers2012

Time-temperature dependence of thermomechanical recovery of cold-curing structural adhesives

Julia De Castro San Roman Fest, Thomas Keller, Omar Moussa, Anastasios Vassilopoulos

The thermomechanical recovery behavior of a commercial cold-curing structural epoxy adhesive was investigated. Exposing the adhesive to temperatures above the glass transition temperature T-g significantly increased the latter although the curing degree in ...

2012

Page 9 sur 16