Publications de Behzad Dehghan Manshadi

Post-wrinkling behavior of webs in GFRP cell-core sandwich structures

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

Similarly to the post-buckling behavior of steel girder webs, the post-wrinkling behavior of glass fiber reinforced polymer (GFRP) cell-core sandwich webs can increase their ultimate shear strength. Post wrinkling is, however, different from post-buckling ...

Elsevier2016

An iterative analytical/experimental study of bridging in delamination of the double cantilever beam specimen

John Botsis, Behzad Dehghan Manshadi, Anastasios Vassilopoulos, Ebrahim Farmand Ashtiani

Large scale bridging in mode-I delamination of layered composites is an important toughening mechanism. While its extent depends on constituent materials, it is also influenced by specimen geometry. Here, an analytical approach is adopted to express the th ...

Elsevier2014

Monitoring strain gradients in adhesive composite joints by embedding fibre Bragg grating sensors

Hans Georg Limberger, John Botsis, Véronique Michaud, Behzad Dehghan Manshadi, Georgios Violakis, Luis Pablo Canal Casado

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

A combined experimental/numerical study of the scaling effects on mode I delamination of GFRP

John Botsis, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

Bridging by intact fibers is an important toughening mechanism in composite materials. However, a direct experimental evaluation of its contribution is difficult to achieve and in the case of large scale bridging the thickness, h, may have an important inf ...

Elsevier2013

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

Instability of Thin-Walled GFRP Webs in Cell-Core Sandwiches under Combined Bending and Shear Loads

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

An analytical investigation of the buckling/wrinkling behavior of GFRP webs in cell-core sandwiches subjected to combined in-plane shear and bending stresses is conducted. Web-core panels are modeled as long orthotropic plates stabilized by a relatively th ...

2012

Biaxial Wrinkling of Thin-Walled GFRP Webs in Cell-Core Sandwiches

Behzad Dehghan Manshadi

Fiber-reinforced polymer (FRP) sandwich structures offer several advantages compared to structures made of traditional materials, such as high specific strength, good corrosion resistance, low thermal conductivity and rapid component installation. In this ...

EPFL2011

Contribution to shear wrinkling of GFRP webs in cell-core sandwiches

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

Glass-fiber-reinforced polymer (GFRP) cell-core sandwiches are composed of outer GFRP face sheets, a foam core, and a grid of GFRP webs integrated into the core to reinforce the shear load capacity. One of the critical failure modes of cell-core sandwich s ...

American Society of Civil Engineers2011

Shear buckling of GFRP beams webs

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

Slender webs of glass fiber-reinforced polymer (GFRP) beams are sensitive to shear buckling. Shear buckling can bee seen as an in-plane biaxial compression-tension buckling problem. The transverse tensile load thereby delays the onset of buckling and incre ...

Springer-Verlag New York, Ms Ingrid Cunningham, 175 Fifth Ave, New York, Ny 10010 Usa2011

Shear Buckling Resistance of GFRP Plate Girders

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

Thin webs of glass-fiber-reinforced polymer (GFRP) girders are sensitive to shear buckling, which can be considered an in-plane biaxial compression-tension buckling problem, according to the rotated stress field theory. An extensive experimental study was ...

American Society of Civil Engineers2011

A computational tool for the life prediction of GFRP laminates under irregular complex stress states: influence of the fatigue failure criterion

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos, Roohollah Sarfaraz Khabbaz

A new computational tool for the fatigue life prediction of composite materials, designated CCfatigue, is presented in this paper. This new software has been developed based on a well-established phenomenological fatigue life prediction methodology. It is ...

Elsevier2010

Influence of the constant life diagram formulation on the fatigue life prediction of composite materials

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

The influence of the constant life diagram (CLD) formulation on the fatigue life prediction of composite materials was examined. Most commonly used and recently proposed CLDs applied on composite materials fatigue data are presented and their applicability ...

Elsevier2010

Thermomechanical behavior of multifunctional GFRP sandwich structures with encapsulated photovoltaic cells

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

The feasibility of encapsulating solar cells into the glass fiber-reinforced polymer (GFRP) skins of load-bearing and thermally insulating sandwich elements with foam cores has been evaluated. Exposure of the encapsulated cells to artificial sunlight led t ...

American Society of Civil Engineers2010

Shear wrinkling of GFRP webs in cell-core sanwiches

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

Glass fiber-reinforced (GFRP) cell-core sandwich structures are increasingly used in bridge deck and roof construction. GFRP cell-core sandwiches are composed of the outer GFRP face sheets, a foam core and a grid of GFRP webs integrated into the core in or ...

Springer-Verlag New York, Ms Ingrid Cunningham, 175 Fifth Ave, New York, Ny 10010 Usa2010

PNL constant life diagram formulation for FRP composites materials

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

2010

Piecewise non-linear constant life diagram formulation for FRP composite materials

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

A new formulation for predicting an asymmetric, piecewise non-linear constant life diagram (CLD) is introduced in this paper. The development of the new model is based on the representation of the fatigue data on the stress ratio (R)-stress amplitude (σa) ...

Elsevier2010

A computational tool for the fatigue life prediction of composite materials

Thomas Keller, Behzad Dehghan Manshadi, Anastasios Vassilopoulos

2009