Faculté des Sciences appliquées
Faculté des Sciences appliquées

Displacement Capacity of Short Coupling Beams

Trandafir, Alexandru ULiège
Promotor(s) : Mihaylov, Boyan ULiège
Date of defense : 26-Jun-2019/27-Jun-2019 • Permalink :
Title : Displacement Capacity of Short Coupling Beams
Author : Trandafir, Alexandru ULiège
Date of defense  : 26-Jun-2019/27-Jun-2019
Advisor(s) : Mihaylov, Boyan ULiège
Committee's member(s) : Franssen, Jean-Marc ULiège
Demonceau, Jean-François ULiège
Popa, Viorel 
Language : English
Discipline(s) : Engineering, computing & technology > Civil engineering
Target public : Researchers
Professionals of domain
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en ingénieur civil des constructions, à finalité spécialisée en "civil engineering"
Faculty: Master thesis of the Faculté des Sciences appliquées


[en] Reinforced concrete coupled walls are an efficient structural system for medium to tall buildings
which provides large stiffness and strength against lateral loads. The coupling of the
individual wall units is typically provided by short and stiff coupling beams which deflect in
double curvature under high shear stresses. These members are working predominantly in
shear and develop complex deformation patterns. For this reason they cannot be modelled
based on the classical plane-sections-remain-plane hypothesis, and are typically designed to
suppress brittle shear failures along wide diagonal cracks based on strut-and-tie models. In
this way, the failure of the beam occurs in the end sections with crushing of the concrete prior
to or after yielding of the flexural reinforcement. Such failures occur with sliding deformations
(sliding shear failure) and limit the displacement capacity and ductility of the member.

It is therefore important for design to be able to predict the ductility of the coupling beams,
taking into account the detrimental effect of the high shear force in the end sections. However,
because strut-and-tie models are inherently conservative, being originally developed
for monotonic loading conditions, they can result in very large amounts of shear reinforcement
and, in addition, do not provide information about the deformation capacity of coupling
beams which is important for performance-based seismic design. Furthermore, because coupling
beams are designed to undergo large inelastic load cycles under seismic loading, they
may be susceptible to premature failures. Such failures have been observed when beams were
loaded in a certain direction after significant yielding of the flexural reinforcement in the opposite

To address these challenges, this paper discusses a two-parameter kinematic theory (2PKT)
for the shear strength and deformation patterns of short coupling beams. The 2PKT approach
is situated between simple and conservative strut-and-tie models and complex nonlinear finite
element (FE) models. While FE models use a large number of degrees of freedom (DOFs) to
describe the deformation patterns in coupling beams, the 2PKT method is based on a kinematic
model with only two DOFs.

This thesis presents the development of a mechanical model and formulation for predicting
the displacement capacity and ductility of conventionally reinforced short coupling beams
susceptible to different shear-dominated failure modes. It is shown that this approach captures
well the global and local deformations measured in test specimens with detailed instrumentation.
Available experimental data from the literature and project ARCO (Mihaylov et al.,
2019) is used to establish key modelling assumptions and to validate the models.

For all tests considered in this study, the 2PKT approach for diagonal tension failure
produced an average shear strength experimental-to-predicted ratio of 0.99 and a coefficient
of variation of 11.05%. The 2PKT model for sliding shear and shear compression failures
yielded an average shear strength experimental-to-predicted ratio of 0.99 and a coefficient of
variation of 9.47%.



Access Trandafir2019_Displacement Capacity of Short Coupling Beams.pdf
Description: TFE
Size: 14.75 MB
Format: Adobe PDF
Access Trandafir2019_Summary.pdf
Description: Summary
Size: 287.1 kB
Format: Adobe PDF


  • Trandafir, Alexandru ULiège Université de Liège > Master ingé. civ. constr., fin.


Committee's member(s)

  • Franssen, Jean-Marc ULiège Université de Liège - ULiège > Département ArGEnCo > Ingénierie du feu
    ORBi View his publications on ORBi
  • Demonceau, Jean-François ULiège Université de Liège - ULiège > Département ArGEnCo > Département ArGEnCo
    ORBi View his publications on ORBi
  • Popa, Viorel Technical University of Civil Engineering Bucharest > Reinforced Concrete Structures
  • Total number of views 17
  • Total number of downloads 2

All documents available on MatheO are protected by copyright and subject to the usual rules for fair use.
The University of Liège does not guarantee the scientific quality of these students' works or the accuracy of all the information they contain.