3,580 research outputs found
A numerical study on impact and compression after impact behaviour of variable angle tow laminates
Time Varying Cyclical Analysis for Economies in Transition
The identification of a possible European business cycle has been inconclusive and is complicated by the enlargement to the new member states and their transition to market economies. This paper shows how to decompose a business cycle into a time-frequency framework in a way that allows us to accommodate structural breaks and nonstationary variables. To illustrate, calculations of the growth rate spectrum and coherences for the Hungarian, Polish, German and French economies show the instability of the transition period. However, since then there has been convergence on the Eurozone economy at short cycle lengths, but little convergence in long cycles. We argue that this shows evidence of nominal convergence, but little real convergence. The Maastricht criteria for membership of the Euro therefore need to be adapted to test for real convergence.Time-Frequency Analysis, Coherence, Growth Rates, Business Cycle
Are Capital Markets Efficient? Evidence from the Term Structure of Interest Rates in Europe
This paper investigates the uncovered interest parity hypothesis in an unusual way. We provide empirical evidence on the efficiency of capital markets using a time domain approach. However, a common prediction from theoretical models is that inefficient capital markets cause greater volatility of the observed time series. By using cross spectral analysis we are able to test this proposition directly. We show, in particular, how this can be done for time-varying models and time-varying spectra. We use our techniques to examine the changing stability of the relationship between British and German interest rates during and following the ERM crisis of 1992/3.
Celebrate Jesus mission : an exploration of pastoral experiences
https://place.asburyseminary.edu/ecommonsatsdissertations/1195/thumbnail.jp
Designing curation for student engagement
In this article we discuss the ways students currently engage with, and navigate through, their learning resources. Working from the argument that students now read and research in ways that privilege assembly, visualisation and interconnection, we propose that questions of student engagement can be opened up profitably by concentrating on a particular trope of learning and assembly. That trope is âcurationâ and we explore how this approach and activity might be used to enhance student learning, creativity and ownership. In our discussion we explore particular theories of curation, âbricolageâ and collaborative assembly, and explain ways in which these are directly relevant to todayâs patterns and habits of student scholarship. After offering case-studies of curation pedagogy at the scales of module, programme, project and institution, we conclude by visualising and explaining our âcuration learning cycleâ. In this way, we tie theory, case-studies and taxonomy together to propose a curriculum design approach that heightens student learning and engagement
Advanced numerical modelling techniques for the structural design of composite tidal turbine blades
Cohesive/Adhesive failure interaction in ductile adhesive joints Part I:A smeared-crack model for cohesive failure
AbstractThis paper proposes a new methodology for the finite element (FE) modelling of failure in adhesively bonded joint. Unlike current methods, cohesive and adhesive failures are treated separately. Initial results show the method׳s ability to give accurate prediction of failure of adhesive joints subjected to thickness-induced constraint and complex multi-axial loading using a single set of material parameters. The present paper (part I), focuses on the development of a smeared-crack model for cohesive failure. Model verification and validation are performed comparing the model predictions with experimental data from 3 point bending End Notched Flexure (3ENF) and Double Cantilever Beam (DCB) fracture tests conducted on adhesively bonded composite panels of different adhesive thicknesses
Predicting the notched strength of large quasi-isotropic composite laminates based on small specimen tests
Modelling the effect of gaps and overlaps in automated fibre placement (AFP)-manufactured laminates
AbstractIn automated fibre placement (AFP) process, gaps and overlaps parallel to the fibre direction can be introduced between the adjoining tapes. These gaps and overlaps can cause a reduction in strength compared with pristine conditions. Finite element modelling is an effective way to understand how the size and distribution of such gaps and overlaps influences the strength and failure development. Many modelling work showed that out-of-plane waviness and ply thickness variations caused by gaps and overlaps play an important role in inducing the strength knock-down; however, there has been a lack of effective way to explicitly model the ply waviness, which constrained the relevant research. In this work, 3D meshing tools were developed to automatically generate ply-by-ply models with gaps and overlaps. Intra-ply and inter-ply cohesive elements are also automatically inserted in the model to capture the influence of splitting and delamination. Out-of-plane waviness and ply thickness variations caused by gaps and overlaps are automatically modelled. Models with various sizes and distribution of gaps and overlaps were built to predict the reduction of strength as a function of the magnitude and type of the defects. Results of gap and overlap models will be used to guide future experimental characterization of simulated AFP process defects, manufactured by hand layup from pre-preg tape.</jats:p
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