Home

Person

Thomas Keller

About
Privacy
Disclaimer

Graph Chatbot

Related publications (309)

Page 7 of 16

Modeling of direct load transmission in sandwich beams with lightweight concrete

Thomas Keller, Till Vallée, Erika Schaumann

The direct load transmission behavior of hybrid sandwich beams consisting of a bottom fiber-reinforced polymer skin and a top concrete skin was investigated experimentally. The sandwich core consisted of lightweight concretes of different brittleness (sand ...

2009

Experimental investigation of rotational behavior of pseudo-ductile adhesive angle joints exhibiting variable strain rate

Thomas Keller, Ghazaleh Eslami, Abdolvahid Movahedirad

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

Progressive failure process of adhesively bonded joints composed of pultruded GFRP

Thomas Keller

Adhesively bonded joints are being used increasingly in civil engineering structures, especially for joints comprising pultruded glass fiber reinforced polymer (GFRP) laminates. The layered material architecture, however, leads to a complex delamination fa ...

2008

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

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

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

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

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

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

Thomas Keller, Anastasios Vassilopoulos, Omar Moussa

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

Modeling of strength degradation for fiber-reinforced polymer composites in fire

Thomas Keller, Yu Bai

A model for predicting composite material strength degradation under elevated and high temperatures is proposed. This model is based on the morphology of the mixture of materials in different states. The degradation of resin-dominated shear strength can be ...

2009

System transverse in-plane shear stiffness of pultruded GFRP bridge decks

Thomas Keller, Julia De Castro San Roman Fest, Sonia Yanes Armas

The static transverse behavior of two pultruded GFRP deck systems with trapezoidal (DS) and triangular (AS) cell cross-sectional geometry was experimentally investigated in order to study their transverse in-plane shear stiffness. Symmetric three-point ben ...

Elsevier2016

Temperature effect on fatigue behavior of basalt fiber-reinforced polymer composites

Thomas Keller, Anastasios Vassilopoulos

In this study, the temperature effect on the static and tension–tension fatigue behavior of basalt fiber‐reinforced epoxy polymer (BFRP) composites is investigated. The S–N curves, energy dissipation, stiffness degradation, and displacement increment with ...

Wiley2019

Effect of temperature on kinking failure mode of non-slender glass fiber-reinforced polymer specimens

Thomas Keller, Anastasios Vassilopoulos, Wei Sun

The kink behavior of non-slender glass fiber-reinforced epoxy prismatic specimens of variable length and fiber volume fraction at temperatures ranging from 25 degrees C to 125 degrees C was investigated. Splitting failure occurred at the glassy state while ...

Elsevier2015

Aramid/glass fiber-reinforced thermal break - thermal and structural performance

Thomas Keller, Julia De Castro San Roman Fest, Kyriaki Goulouti

Energetically weak points in thermally insulated building envelopes are formed by thermal breaks that are implemented to structurally connect external balconies to internal slabs. Current thermal breaks comprise stainless steel bars that penetrate the insu ...

Elsevier2016

FRP-balsa composite sandwich bridge deck with complex core configuration

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

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

2014

Time dependence of material properties of FRP composites in fire

Thomas Keller, Yu Bai

Temperature dependence of physical and mechanical properties is considered in most thermal and mechanical response models for composite materials. Based on thermogravimetry analysis, differential scanning calorimetry, and dynamic mechanical analysis conduc ...

2009

Ductility, recovery and strain rate dependency of an acrylic structural adhesive

Thomas Keller, Anastasios Vassilopoulos, Myrsini Angelidi

The ductility and time-dependent recovery of a ductile acrylic adhesive were investigated in this work. The quasi-static true tensile and compressive strain behaviors were examined at different strain rates, taking large deformations into account. Yield st ...

Elsevier2017

Experimental investigation on the moment-rotation performance of pultruded FRP web-flange junctions

Thomas Keller

This paper aims to present an experimental investigation on the behavior of web-flange junctions (WFJs) rotational stiffness of pultruded fiber-reinforced polymer composites (FRP). Channels and I-sections were tested using a simple set-up, which was develo ...

ELSEVIER SCI LTD2021

Structural limits of FRP-balsa sandwich decks in bridge construction

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

The span limits of two glass fiber-reinforced polymer (GFRP) bridge concepts involving GFRP-balsa sandwich plates are discussed. The sandwich plates were either used directly as slab bridges or as decks of a hybrid sandwich-steel girder bridges. In the lat ...

Elsevier2014

Long-term design of FRP-PUR web-core sandwich structures in building construction

Thomas Keller, Julia De Castro San Roman Fest, Sonia Yanes Armas

The structural behavior of GFRP-polyurethane (PUR) web-core sandwich structures subjected to sustained loading was investigated. As a basis, a study of the mechanical behavior of rigid PUR foams used as core materials was conducted, with emphasis on creep. ...

Elsevier2017

Direct load transmission in hybrid FRP and lightweight concrete sandwich bridge deck

Thomas Keller, Till Vallée, Erika Schaumann

Direct load transmission experiments on hybrid short-span beam specimens for a novel bridge deck were performed. The sandwich construction consists of three layers: a fiber- reinforced polymer composite (FRP) sheet with T-upstands for the bottom skin, ligh ...

2008

Optimization of multi-directional fiber architecture for resistance and ductility of bolted FRP profile joints

Thomas Keller, Lulu Liu

In view of the low structural efficiency of bolted joints in pultruded fiber-reinforced polymer (FRP) profiles with mainly unidirectional (UD) fiber architecture, off-axis plies were considered as an effective way to improve bolted joint performance. An ex ...

ELSEVIER SCI LTD2020