Stiffness of dowel-type timber connections and its influence on structures Finite element analysis of high performance timber connections and their impact in a case study
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Structural engineering and building technology (MPSEB), MSc
Publicerad
2023
Författare
ABDALLAH, DINA
DIMMING, ANTON
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Timber is one of the oldest construction materials and are used for many purposes
in the field. Although, timber has not been prioritized as a structural material for
multi-storey buildings, today’s new technologies which generate engineering wood
products, allow to build in larger scale than ever before. Connections between
timber members in structural systems are critical details, but detailed design standards
and guidelines for large-scale timber connections are still lacking.
The stiffness and ductility of timber connections are important parameters for the
response of a structural system. However the methods for evaluating stiffness in
standards such as Eurocode 5 are limited. For this reason, detailed information on
stiffness and ductility of connections might be neglected in design process. This
might results in inefficient material utilisation and unknown effects. Therefor, the
aim of this thesis is to analyze the stiffness of timber connections, and the impact
the stiffness can have on a structural system.
The research is accomplished by identifying and using appropriate modeling methods
for dowel-type timber connections, and then investigating the design of a 5-storey
building with timber beam-column structural system. Firstly, the rotational
stiffness of the most used connection in the case study was calculated by finite element
analysis in Abaqus. Then, modified variations of the chosen connection were analysed
to study the influence of different design choices on the rotational stiffness.
Lastly, the calculated stiffness is inserted to the joints of the model of the reference
building in RFEM software to study the contribution of connection’s stiffness to
internal forces and global deformations.
The findings of this thesis can be summed up to that other than those provided by
the standards, there are applicable methods that provide more sophisticated load-
deformation relations and estimate stiffness for dowel-type timber connections. For
the studied case, the stiffness of the beam-to-column connections had limited impact
on the global deformations and some impact on internal forces in the structural
system. In addition, accounting for stiffness in the joints of a timber beam reduces
the span moment and might allow for reduced design cross-sectional area. However,
some more aspects and parameters than the treated ones in this thesis should be
taken into account when rising the stiffness and ductility of a connection.
Beskrivning
Ämne/nyckelord
Rotational stiffness, ductility, glulam, dowel-type connection, structural system, shear plane, FEM, Eurocode.