3,195 research outputs found
Multiscale Surrogate Modeling and Uncertainty Quantification for Periodic Composite Structures
Computational modeling of the structural behavior of continuous fiber
composite materials often takes into account the periodicity of the underlying
micro-structure. A well established method dealing with the structural behavior
of periodic micro-structures is the so- called Asymptotic Expansion
Homogenization (AEH). By considering a periodic perturbation of the material
displacement, scale bridging functions, also referred to as elastic correctors,
can be derived in order to connect the strains at the level of the
macro-structure with micro- structural strains. For complicated inhomogeneous
micro-structures, the derivation of such functions is usually performed by the
numerical solution of a PDE problem - typically with the Finite Element Method.
Moreover, when dealing with uncertain micro-structural geometry and material
parameters, there is considerable uncertainty introduced in the actual stresses
experienced by the materials. Due to the high computational cost of computing
the elastic correctors, the choice of a pure Monte-Carlo approach for dealing
with the inevitable material and geometric uncertainties is clearly
computationally intractable. This problem is even more pronounced when the
effect of damage in the micro-scale is considered, where re-evaluation of the
micro-structural representative volume element is necessary for every occurring
damage. The novelty in this paper is that a non-intrusive surrogate modeling
approach is employed with the purpose of directly bridging the macro-scale
behavior of the structure with the material behavior in the micro-scale,
therefore reducing the number of costly evaluations of corrector functions,
allowing for future developments on the incorporation of fatigue or static
damage in the analysis of composite structural components.Comment: Appeared in UNCECOMP 201
Design and implementation of a platform for smart connected school buildings
We have designed and implemented a platform that enables monitoring and actuation in multiple buildings, that has been utilised in the context of a research project in Greece, focusing on public school buildings. The Green Mindset project has installed IoT devices in 12 Greek public schools to monitor energy consumption, along with indoor and outdoor environmental parameters. We present the architecture and actual deployment of our system, along with a first set of findings
Numerical study of asymmetric keel hydrodynamic performance through advanced CFD
The hydrodynamics of an asymmetric IACC yacht keel at angle of yaw are presented using simulations performed by advanced computational fluid dynamics using state-of-the-art software. The aim of the paper is to continue working on the improvement of numerical viscous flow predictions for high-performance yachts using Large Eddy Simulation and Detached Eddy Simulation on unstructured grids. Quantitative comparisons of global forces acting on the keel and wake survey are carried out. Qualitative comparisons include flow visualisation, unsteady and separated flow and other features. Star-CCM+ and the trimmed cell method give better forces and wake prediction compared to the unstructured mesh of ANSYS Fluent. Both solvers give good flow visualisation near and far field of the keel
Smart materials application on high performance sailing yachts for energy harvesting
Piezoelectric patches are bounded on a keel bulb in order to harvest vibration energy by converting electrical output. Unsteady computational fluid dynamics method is also used to find the structural boundary condition such as the hydrodynamic pressure fluctuation. Finite element analysis (FEM) is used to find structural and electrical responses
Gender differences in colour naming
Gender differences in colour naming were explored using a web-based experiment in English. Each participant named twenty colours selected from 600 Munsell samples, presented one at a time against a neutral background. Colour names and typing onset response times were registered. For the eleven basic colour terms, elicitation frequency was comparable for both genders. Females demonstrated more elaborated colour vocabulary, with more descriptors in general and more non-basic monolexemic terms; they also named colours faster than males. The two genders differ in the repertoire of frequent colour terms: a Bayesian synthetic observer revealed that women segment colour space linguistically more densely in the âwarmâ area whereas men do so in the âcoolâ area. Current ânurtureâ and ânatureâ explanations of why females excel in colour naming behaviour are considered
Elastic-plastic finite element analysis of cracked solids Progress report
Elastic-plastic finite element analysis of cracked solid
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