433 research outputs found
Analysis of textile composite structures with finite Volume-p-Elements
Anisotropic textile composites show nonlinear deformation and complex fai-
lure behaviour. In particular three-dimensional reinforced textile composites
are characterised by an orthotropic material behaviour. To achieve the full po-
tential of textile composites the material and especially the failure behaviour
has to be analysed particularly for regions dominated by three-dimensional
stress distributions, e. g. load introduction areas.
For these purposes finite volume-p-elements based on hierarchical shape
functions are being developed. Furthermore the constitutive model is en-
hanced to simulate material degradation and failure processes. Based on an
anisotropic continuum damage model the material degradation is described
with tensorial damage variables that characterise the crack density observed
in experimental studies of Non-Crimp-Fabrics with E-Glass fibres. The deter-
mination of the onset of degradation and the strength prediction is enabled
by coupling the damage model with a failure criterion for three-dimensional
reinforced plastics.
Due to control the spatial adaptivity of polynomial order of the shape functi-
ons different a posteriori error estimators are evaluated and compared espe-
cially with respect to the applicability on structural models representing or-
thotropic material behaviour.
Experimental analyses were used to determine the parameters of the consti-
tutive model. Besides the in-plane properties the through-thickness material
properties are assumed to be primarily important for textile composites. The-
refore a modified Arcan testing device was developed which provides test
results for biaxial tension and shear load combinations taking the material
thickness direction into account.
Finally simulations and experimental analyses of a thick double holed plate -
the loadintroduction of an elevator bucket - demonstrate the applicability of
the material model and finite element implementation
Complex Societies and the Growth of the Law
While a large number of informal factors influence how people interact,
modern societies rely upon law as a primary mechanism to formally control human
behaviour. How legal rules impact societal development depends on the interplay
between two types of actors: the people who create the rules and the people to
which the rules potentially apply. We hypothesise that an increasingly diverse
and interconnected society might create increasingly diverse and interconnected
rules, and assert that legal networks provide a useful lens through which to
observe the interaction between law and society. To evaluate these
propositions, we present a novel and generalizable model of statutory materials
as multidimensional, time-evolving document networks. Applying this model to
the federal legislation of the United States and Germany, we find impressive
expansion in the size and complexity of laws over the past two and a half
decades. We investigate the sources of this development using methods from
network science and natural language processing. To allow for cross-country
comparisons over time, we algorithmically reorganise the legislative materials
of the United States and Germany into cluster families that reflect legal
topics. This reorganisation reveals that the main driver behind the growth of
the law in both jurisdictions is the expansion of the welfare state, backed by
an expansion of the tax state.Comment: 22 pages, 6 figures (main paper); 28 pages, 11 figures (supplementary
information
Measuring Law Over Time: A Network Analytical Framework with an Application to Statutes and Regulations in the United States and Germany
How do complex social systems evolve in the modern world? This question lies
at the heart of social physics, and network analysis has proven critical in
providing answers to it. In recent years, network analysis has also been used
to gain a quantitative understanding of law as a complex adaptive system, but
most research has focused on legal documents of a single type, and there exists
no unified framework for quantitative legal document analysis using network
analytical tools. Against this background, we present a comprehensive framework
for analyzing legal documents as multi-dimensional, dynamic document networks.
We demonstrate the utility of this framework by applying it to an original
dataset of statutes and regulations from two different countries, the United
States and Germany, spanning more than twenty years (1998-2019). Our framework
provides tools for assessing the size and connectivity of the legal system as
viewed through the lens of specific document collections as well as for
tracking the evolution of individual legal documents over time. Implementing
the framework for our dataset, we find that at the federal level, the United
States legal system is increasingly dominated by regulations, whereas the
German legal system remains governed by statutes. This holds regardless of
whether we measure the systems at the macro, the meso, or the micro level.Comment: 32 pages, 13 figures (main paper); 32 pages, 14 figures
(supplementary information
Multilevel modelling of mechanical properties of textile composites: ITOOL Project
The paper presents an overview of the multi-level modelling of textile composites in the ITOOL project, focusing on the models of textile reinforcements, which serve as a basis for micromechanical models of textile composites on the unit cell level. The modelling is performed using finite element analysis (FEA) or approximate methods (method of inclusions), which provide local stiffness and damage information to FEA of composite part on the macro-level
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