Numerical Simulation and Experimental Investigation of the Fracture Behaviour of an Electron Beam Welded Steel Joint, 1st ed. 2018 Springer Theses Series
Langue : Anglais
In this thesis, the author investigates experimentally and numerically
the fracture behavior of an electron beam welded joint made from
two butt S355 plates. The 2D Rousselier model, the Gurson-Tvergaard-
Needleman (GTN) model and the cohesive zone model (CZM) were
adopted to predict the crack propagation of thick compact tension (CT)
specimens. Advantages and disadvantages of the three mentioned models
are discussed. The cohesive zone model is suggested as it is easy to use
for scientists & engineers because the CZM has less model parameters
and can be used to simulate arbitrary crack propagation. The results
shown in this thesis help to evaluate the fracture behavior of a metallic
material. A 3D optical deformation measurement system (ARAMIS) and
the synchrotron radiation-computed laminography (SRCL) techniquereveal for the first time the damage evolution on the surfaceof the sample
and inside a thin sheet specimen obtained from steel S355. Damage
evolution by void initiation, growth and coalescence are visualized in
2D and 3D laminographic images. Two fracture types, i.e., a flat crack
propagation originated from void initiation, growth and coalescence
and a shear coalescence mechanism are visualized in 2D and 3D images
of laminographic data, showing the complexity of real fracture. In
the dissertation, the 3D Rousselier model is applied for the first time
successfully to predict different microcrack shapes before shear cracks
arise by defining the finite elements in front of the initial notch with
inhomogeneous f0-values. The influence of the distribution of inclusions
on the fracture shape is also discussed. For the analyzed material, a
homogeneous distribution of particles in the material provides the
highest resistance to fracture.
Introduction.- Scientific background.- Characterization of steel S355 electron beam welded (EBW) joints.- The Rousselier model.- The Gurson-Tvergaard-Needleman (GTN) model.- The Cohesive zone model.- Optical measurement of crack propagation with the ARAMIS system.- In situ laminography investigation of damage evolution in S355 base material.- Summary and Outlook.
Haoyun Tu is an Assistant Professor at the School of Aerospace Engineering and Applied Mechanics, Tongji University, PR China. He received his BE and ME from Northwestern Polytechnical University, China and Dr.-Ing. from University of Stuttgart, Germany. His research interests are on fracture mechanism of metals and welded joints from metals with experimental and finite element methods as well as on characterization techniques such as 3D optical deformation measurement and Synchrotron radiation-computed laminography (SRCL).
Suggests cohesive zone model as the ideal for the prediction of crack propagation Concludes essential infomation for the evaluation of the fracture behaviour of metallic materials Reveals the nature of the fracture mechanism of an electron beam welded joint Includes supplementary material: sn.pub/extras
Date de parution : 09-2018
Ouvrage de 171 p.
15.5x23.5 cm
Date de parution : 10-2017
Ouvrage de 171 p.
15.5x23.5 cm
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