Abstract
A new continuum damage model, the wing crack damage (WCD)
model, was developed for the analysis of brittle failure
of transversely isotropic solids. Special attention was
paid to the analysis of axial splitting under compression
and tensile cracking under tension.
In addition to the WCD model a three-dimensional version
of the damage model proposed by Murakami and Kamiya was
enhanced and implemented in ABAQUS/Standard FE software.
The proposed WCD model is based on the use of the damage
vector. The vector represents both the normal direction
of the surface of the plane crack and the size of the
damaged area. Damaging induces anisotropy in an
originally transversely isotropic material. The evolution
equations for damage are motivated by the wing crack
growth mechanism. The evolution is based on propagation
of pre-existing damage.
The proposed model enables modelling of pre-existing
cracks. The feature can be exploited in studying the
effect of orientation and size distribution of
pre-existing cracks on the failure of materials. The
model was implemented in ABAQUS/Standard FE software as a
user subroutine.
The unsymmetrical behaviour of cracked materials under
tension and compression due to the opening and closure of
cracks is taken into account in the proposed model. In
the work it was shown that the widely used strain-based
crack closure criteria cannot be reliably applied in a
two- and three-dimensional stress state. To attain a
deformation localisation zone of finite width, a damage
rate-dependent damage surface was introduced.
The validity of the proposed model was verified by
testing it against five basic structures composed of
known natural materials (ice, marble and concrete). The
numerical simulations revealed the capability of the
model in modelling brittle failure modes of transversely
isotropic materials.
Original language | English |
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Qualification | Doctor Degree |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 20 Apr 2007 |
Place of Publication | Espoo |
Publisher | |
Print ISBNs | 978-951-38-6995-3 |
Electronic ISBNs | 978-951-38-6996-0 |
Publication status | Published - 2007 |
MoE publication type | G4 Doctoral dissertation (monograph) |
Keywords
- failure mechanics
- brittle failure
- anisotropy
- continuum mechanics
- damage models
- finite element analysis
- solid materials
- structural analysis
- three-dimensional
- transversal isotropy
- wing crack