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© 2015 Optical Society of America. The authors thank Maite Irigoyen for her encouragement and many useful comments during the preparation of this work. Funding: Direccion General de Universidades e Investigacion, Comunidad de Madrid (Spain) (SEGVAUTO-TRIES CM S2013/MIT-2713); Ministerio de Economia y Competitividad (MINECO) (DPI2011-27851)., A superachromatic quarter-wave retarder using an arbitrary number of waveplates in a broadband spectral range has been proposed. Their design is based on the optimization of a merit function, the achromatism degree (AcD), which represents a global behavior metric for the retardation. By means of this technique, the thickness and azimuth of each waveplate is determined. The achromatism degree is a measure of the distance between the overall retardation and a target retardation weighted by the spectrum of the incident light. We report on a particular case where all waveplates are made of quartz. As application examples, the design of a quarter-wave retarder using two, three, and four waveplates in the spectral ranges of 500-700 nm and 400-1000 nm was studied. The numerical results show that for these ranges, the best designs obtained present a maximum difference of 0.013 degrees and 0.010 degrees with respect to the target retardation, respectively. In addition, an analysis of their achromatic stability is presented. These results can be applied in the aerospace industry, spectroscopic ellipsometry, and spectrogoniometry, among others., Comunidad de Madrid, Ministerio de Economia y Competitividad (MINECO), Depto. de Óptica, Fac. de Ciencias Físicas, TRUE, pub

We report direct numerical simulations of the fully developed turbulent natural convection flow of a Boussinesq fluid (Pr = 0.71) in a vertical channel. One wall is heated with a constant heat flux and the other is assumed to be perfectly insulated. Simulations were performed at three different Rayleigh numbers (Ra = 5 × 105, 106 and 5 × 106). Predictions of the time averaged velocities, temperatures and intensities of the fluctuations agree with experiments reported in the literature. Under the fully developed flow conditions considered in this study the shear stress is greater on thermally active wall than that on the adiabatic wall, but the turbulent intensities and the turbulent shear stress are greater near the insulated wall. Conversely, the intensities of the temperature fluctuations and turbulent heat fluxes are higher near the thermally active wall than those near the adiabatic wall. Contrary to the vertical channel with constant but different wall temperatures, where buoyancy and turbulent shear dominate the generation of turbulent kinetic energy, in the asymmetrically heated channel the turbulent shear stress is the principal mechanism of turbulent kinetic energy production as in a forced convection channel flow.

The effect of the slit length on the acoustic transfer impedance of micro-slit plates (MSPs) is investigated in the linear and non-linear regime for a specific slit geometry. This geometry is inspired by slits obtained by cutting and bending the plate. MSPs are plates with arrays of slit-shaped perforations, with the width of the order of the acoustic viscous boundary layer thickness. Impedance tube measurements on two accurately manufactured plates are compared to numerical solution of the Linearized Navier-Stokes equations and to analytical limits. The impedance of the plate is obtained by the impedance of a single slit divided by the plate porosity. The resistance of a slit is independent on the slit length and on the plate porosity. In the linear regime the resistance is accurately predicted by a two-dimensional numerical model. In the non-linear regime, the resistance is strongly dependent on the amplitude of the acoustic waves. The inertance of the slit is weakly dependent on the slit length and on the plate porosity, for low and moderate amplitudes. For high amplitudes, a complicated amplitude dependency of the inertia of short slits is found. One expects that most of the conclusions obtained can be generalized to other slit geometries.

The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner. Hand fractures are the most common fractures presenting at both accident and emergency and within orthopedic clinics. Appropriate evaluation at first presentation, as well as during their management, can significantly prevent both morbidity and disability to a patient. These decisions are dependent on a wide range of factors including age, hand dominance, occupation, and co-morbidities. A fracture is best described as a soft tissue injury with an associated bony injury. Despite this being the case, this paper intends to deal mainly with the bone injury and aims to discuss both the timing, as well as the methods available, of hand fracture management. Fractures of the metacarpal are the most common of hand fractures accounting for up to 40% [1, 2] and are usually the injury described as ‘a broken hand’ by the general public.  For discussion purposes fractures of the metacarpals are best described anatomically and the digits can be grouped together, although the fifth metacarpal is often expressed on its own as the ‘boxer fracture’ and accounts for a quarter of all metacarpal fractures [2]. Likewise, due to anatomical and functional variance the first metacarpal is generally classified as a separate entity which is not included in this Article.

[ES] Estudio analítico de placas piezoeléctricas por el método de Galerkin y validación de resultados con dos programas de elementos finitos: FEAP y COMSOL. Aplicación particularizada para el caso de la producción de energía a través de las olas marítimas con una placa en voladizo., [EN] Analitic study of piezoelectric plates using the Galerkin method and verified with two finite elements programs: FEAP and COMSOL. Case of energy production through sea waves with a cantilever plate.

This article provides a brief overview of the Khorezmian ceramics and discusses the technology of the pottery. The peculiarities of pottery are also introduced

Object of research of article is the drawing of bars plate in the refiners at refining of chips and wood pulp. On the basis of the theory of contact interaction of bars influence of the drawing of plate on characteristics of contact processes is investigated. The friction coefficient between plate decreases at increase in density of contact of bars. At increase in an angle of crossing of bars rotor and stator and refining of pulp with concentration up to 6% the coefficient of friction decreases. At increase in an angle of crossing of bars chips and pulp with concentration over 10% the coefficient of friction increases. Therefore it is recommended to increase the angle of crossing of bars rotor and stator at refining of pulp of low concentration, and at refining of pulp of concentration over 10% and chips - to reduce, up to a radial arrangement. © 2021 Institute of Physics Publishing. All rights reserved.

The use of timber in building structures is steadily increasing. cross laminated timber (CLT) is an engineered wood product made of an uneven number of layers of lamellas glued at an angle of 90 degrees to each other. This gives CLT high stiffness and strength to bending in all directions, and capability of taking load both in-plane and out-of-plane. Due to the large size of CLT elements, they allow for quick assembly of strong structures. Due to both economic and environmental reasons it is important for producers of CLT to optimize the use of the wood material by using the timber with higher stiffness and strength where it is most needed. This thesis is about evaluating the bending and shear stiffness of CLT elements, when used as plates, depending on the quality of wood used in the different layers. Four-point bending tests are carried out on elements of different compositions and a parametrized finite element model is created. Thus, the model is validated on the basis of experimental tests to evaluate the influence of different quality of different layers. The measured dynamic MoE proved to have good potential to be used as the longitudinal bending stiffness in an FE-model, with a deviation from the experimental tests of less than 1%. There is a strong correlation between the bending stiffness and bending strength of the plates. The effective rolling shear modulus in pine was calculated to be around 170 MPa for pine of dimension 40 x 195 mm2 . Grading the boards into two different classes used for different layers proved to increase the MoE of the plates by 11-17% for 3- and 5-layer CLT.

A novel Kirigami modified corrugated core was proposed recently and its superior crushing performance under static loading was demonstrated. The proposed core is modified from the conventional corrugated core using Kirigami design, where a portion of the corrugated sheet is cut and then folded vertically. The vertical fold-ins of Kirigami modified corrugated core provide extra support and constraints to the adjacent un-folded cell walls, which increase the crushing resistance of a unit cell up to 10 times as previously studied. However, for a panel with multiple unit cells, its longitudinal flexural stiffness and impact resistance could be affected because of the fold-ins. This study investigates its performance and energy absorption under dynamic crushing through pendulum impact tests. Four configurations of panels, including laminated flat plate (FL), conventional corrugated (CC), Kirigami modified corrugated 1 (KC1) and Kirigami modified corrugated 2 (KC2) were tested. Different impact mass, velocities as well as impacting locations were considered. Impact force and rear face centre deflection were measured and compared to evaluate the impact performance of the panels. Superior impact resistance was demonstrated for proposed KC panel over CC panel under all impact scenarios.

A dual-meta panel functioning as a sacrificial cladding is proposed and its blast mitigation capacity is investigated in this study. The proposed panel possesses the potential to generate bandgaps that target at a specific range of frequencies to stop stress wave propagating through the panel, leading to the favourable stress wave mitigation for structural protection. Aside from the unique stress wave manipulation capability, more energy can be absorbed by a combination of plastic deformation and local resonance. The effectiveness of the proposed panel is validated through numerical simulations. An analytical solution of wave propagation in an ideal meta truss bar is derived to validate the numerical model with good agreement. It is found that the proposed dual-meta panel exhibits an increase in energy absorption, a reduction in transmitted reaction force (up to 30%), and the back plate central displacements (up to 20%) compared to other conventional sandwich panels, e.g. sandwich panel with hollow trusses and solid trusses, in resisting blast loadings. In pursuit of optimizing the performance of the proposed panel, parametric investigations are also conducted to examine the influences of the plate thickness, boundary condition, and the blast load profiles including duration and intensity on the transient response of the proposed dual-meta panel.

David Eder, BSc., Arbeit gesperrt, Universität Innsbruck, Masterarbeit, 2020, (VLID)5320598

An experimental study on the duration of load effects in a glued shear plate dowel joint was conducted. The joint design features a single large diameter dowel for load transfers between members, via external steel plates, which are bonded to the timber with a low stiffness bond line. Due to the low bond line stiffness, the timber element is subjected to a close to uniform shear stress distribution over the bond area. The study comprises a total of 80 test specimens loaded in shear, both parallel and perpendicular to the grain, at three load levels in the range of 50–80% of the short-term failure load. All specimens failed within approximately 110 days in outdoor sheltered conditions during which time deformations were recorded for one specimen of each type and load level. The study found a significantly larger influence of duration of load for this dominant shear action than what is reported in the literature for bending tests. The method of ranked stress was used to determine a suggested reduction factor kmod for the shear plate dowel joint to 0.10 and 0.30 for parallel and perpendicular loading, respectively. This is a rough estimate based upon a 50-year extrapolation of 4-month data. Thus, it must be concluded that the studied shear plate dowel joint is not efficient in terms of long-duration loads in outdoor sheltered climate, and that further studies are needed in order to verify the use in other climates. It is also evident in this study that there is a lack of knowledge and empirical evidence on the duration of load effects in timber for shear loading., QC 20200424

The subject of the researches is reliability of plate of knife refiners. Mathematical model of reliability connecting technical resource of plate with the major factors influencing reliability is offered. Influence of regime, operational, efficiency and protective factors is considered. Recommendations about increase in reliability of plate are developed. Offered technique of reliability research can be used in other machines, for example, in centrifugal pumps. © 2020 Published under licence by IOP Publishing Ltd.

Fabric-reinforced cementitious matrix (FCRMs) are composites that produce lighter and more durable strengthening solutions. In this study, carbon and basalt fabrics were used to manufactured FRCM plate specimens. These plates were subjected to a centered punctual load with different punch diameters. Flexural failure mode was observed. Experimental tests showed that carbon and basalt fabrics improved notably the load capacity and the stiffness of mortar plates compared to unreinforced ones. Moreover, failure in the reinforced plates was progressive, preventing the sudden brittle failure of the unreinforced ones. Analytical and numerical models were adjusted and validated from experimental results, and both have proved to be effective calculation tools. What is more, numerical model allowed to determine a sliding tensile stress for the carbon fabric used in this study., Authors want to thanks the research project SEVERUS (RTI2018-099589-B-I00) of the Spanish Research Agency. Authors also want to acknowledge the support provided by Bernat Almenar Muns during experimental testing. Second author is a Serra Húnter Fellow., Peer Reviewed, Postprint (author's final draft)

En aquest treball s’ha realitzat un procés per aconseguir realitzar un prototip de canvi automàtic mecànic funcional. En els primers punts podem trobar tot l’estudi de les tipologies de bicicletes així com dels seus elements característics com bieles, plats i pinyons. Durant aquest estudi inicial s’ha definit els paràmetres òptims sobre els quals utilitzar el canvi automàtic. Posteriorment s’han definit les condicions dels perfils d’usuaris, les característiques del mercat i les condicions d’ús del canvi. Seguidament amb totes aquestes dades s’ha realitzat un procés sistemàtic de disseny on s’han utilitzat alguns components ja estandarditzats que s’han dimensionat a partir dels càlculs. El resultat de tot l’anterior ha estat un prototip de canvi automàtic mecànic que funciona segons els estàndards marcats (bicicleta de cross country, canvi de marxes de 1x11, biela normalitzada i ciclisme no professional) i que quan s’ha realitzat una simulació de moviment els resultats han sigut bons. Un cop amb aquestes dades s’han redefinit les peces per poder adaptar-les millor a un procés de fabricació i muntatge i amb tot això s’ha realitzat un pressupost estimat que ens permet veure que comparativament amb una bicicleta elèctrica els costos són inferiors., En este trabajo se ha realizado un proceso para conseguir realizar un prototipo de cambio automático mecánico funcional. En los primeros puntos podemos encontrar todo el estudio de las tipologías de las bicicletas, así como de sus elementos característicos como bielas, platos y piñones. Durante este estudio inicial se han definido los parámetros óptimos sobre los cuáles utilizar el cambio automático. Posteriormente se han definido las condiciones de los perfiles de los usuarios, las características del mercado y las condiciones de uso del cambio. Seguidamente con todos esos datos se ha realizado un proceso sistemático de diseño donde se han utilizado algunos componentes ya estandarizados que se han dimensionado a partir de cálculos. El resultado de todo lo anterior ha sido un prototipo de cambio automático mecánico que funciona según los estándares marcados (bicicleta de cross country, cambio de marchas de 1x11, biela normalizada y ciclismo no profesional) y que cuando se ha realizado una simulación los resultados han sido buenos. Una vez con estos datos se han redefinido las piezas para poder adaptarlas mejor a un proceso de fabricación y montaje y con todo esto se ha realizado un presupuesto estimado que nos permite ver que comparativamente con una bicicleta eléctrica los costes son inferiores., In this work, a process has been carried out to achieve a prototype of a functional mechanical automatic transmission. In the first points we can find the whole study of the types of bicycles as well as their characteristic elements such as connecting rods, plates and pinions. During this initial study, the optimal parameters on which to use automatic transmission were defined. Subsequently, the conditions of the user profiles, the characteristics of the market and the conditions of use of the change have been defined. Then, with all of this, a systematic design process has been carried out where some already standardized components have been used that have been dimensioned from the calculations. The result has been a prototype of automatic mechanical change that works according to the marked standards (cross country bike, 1x11 gear change, standard connecting rod and non-professional cycling) and that when a simulation of movement the results have been good. With this, the parts have been redefined to better adapt them to a manufacturing and assembly process, and with all this an estimated budget has been made that allows us to see that compared to an electric bike, the costs are lower.

Among the multitude of ceramic fragments, there occasionally appear handles of unusual shapes, or the remains of large dome-shaped lids. Such vessels were used for food preparation in kitchens with open hearths. Ever since prehistory, they have represented a kitchen appliance in daily use to the present day, and they appear in Roman kitchens as well. Various sources refer to this method of food preparation as sub testu. These vessels’ segments have also been archaeologically confirmed on Roman sites in Pannonia Inferior and Moesia Superior. There is a type of dish called patina in Roman cuisine, similar to modern-day souffle, which was presumably prepared on plates with a flat bottom and curved, convex, or concave walls.

A recently proposed tuning method for resistive-inductive (RL) shunts is implemented in a commercial finite element (FE) code (ANSYS®). A main result of the paper is therefore the consistent formulation of the tuning method in terms of variables directly available as solutions in any commercial FE code: The two natural frequencies associated with short- and open-circuit (SC and OC) electrodes and a modal charge obtained as the electrical SC reaction force. An alternative method is based on quasi-static solutions with SC and OC electrodes, convenient for both numerical analysis and experiments. The proposed shunt tuning method is suitable for implementation in any commercial FE software supporting electromechanical analysis and ANSYS® has been used to assess its accuracy for a piezoelectric smart plate benchmark problem. The method is finally extended to multiple piezoceramic patches, placed symmetrically on the structure and shunted to a single RL network, whereby more vibration modes can be effectively controlled for the specific plate problem.

The paper investigates the effects of the geometrical imperfections in buckling analyses of plated steel elements at elevated temperatures and provides an alternative branch-switching procedure to perform post-buckling analyses without introducing initial imperfections into the model. This procedure is appealing since the choice of appropriate imperfections in classical analyses is not straightforward, above all at elevated temperature. Several numerical analyses show that the choice of the imperfections is not trivial and that the buckling mode may vary with temperature. They also show that the proposed branch-switching procedure is an interesting preliminary tool to understand the instability behaviour of steel structural members., QC 20190315

[EN] We theoretically, numerically, and experimentally analyze the Density-Near-Zero (DNZ) regime of a one-dimensional acoustic metamaterial. This acoustic metamaterial is composed of thin elastic plates periodically clamped in an air-filled waveguide, and the effective dynamic zero mass density is obtained from the strong dispersion around the bandgaps associated with the resonances of the plates. We emphasize the importance of the impedance mismatch between the acoustic metamaterial and the surrounding waveguide at the frequency of the zero effective density in addition to the consequences of the inherent losses. As a result, the frequency of the zero phase propagation, i.e., the acoustic propagation with zero phase delay, is not exactly the frequency of the zero density and lies in the frequency bandgap where the effective density is negative. Considering these limitations, the zero phase propagation is still experimentally observed and a subwavelength acoustic dipole is numerically designed, thus demonstrating the possible realistic implementations of DNZ acoustic metamaterials.

[ES] El presente trabajo final de grado consiste en el diseño, cálculo y mejora de un disco para halterofilia y fitness más resistente a impactos. Se han definido los criterios de diseño y los cálculos de cada uno de los elementos que lo componen, el inserto metálico y el disco de caucho. Se ha llevado a cabo el estudio de los materiales a utilizar para su optimización en términos de resistencia, especialmente a impacto. Para ello se ha desarrollado una simulación en el software de elementos finitos que ofrece el software SolidWorks. Con todos los estudios realizados se muestra una comparativa de los resultados obtenidos en todos los ensayos, así como del precio de cada material y otras condiciones. Finalmente se ha justificado el material escogido y sus procesosde fabricación, concluyendo con unestudio económico del diseño finaly los diversos factores del entorno., [EN] The present final degree project aims to the design, calculation and improvement of a weightlifting and fitness diskwith high impact strength. Design and calculations criteria for both metal insertand discelements have been defined. A deep study of the materials has been carried out in order to figure out their use in terms of resistance, especially on impactbehavior. To achieve this, diverse simulations using Finite Element Method within the commercial software “Solid Works©” have been conducted. After carrying out several experimental tests, a comparison of the test results was undertaken, including the final cost for each material as well as other interesting conditions. Finally, one material from all above materials has been chosen including the best fitting manufacturing process, justified by an economic study concerning the final design and important environmental factors.

[ES] En este trabajo fin de grado, el alumno deberá realizar un estudio de mercado, bocetos, una elección del diseño final mediante un VTP. Realizara planos, renders, cálculos estructurales y presupuesto., [EN] In this final degree project, the student must carry out a market study, sketches, a choice of the final design through a VTP. Make plans, renderings, structural calculations and budget.

The subject of the research is the diagnosis of the technical condition of the plate of knife refiners. The technical diagnosis of a knife plate consists of determining the stability of the inter-knife gap and the degree of the plate wear. The paper explores the dynamic effects of a plate on a fibrous material. It is shown that the main source of high-frequency vibration of the stator is pressure pulses that occur when the rotor and stator knives cross. The influence of the rotor speed and the number and angle of intersection of the plate knives on the nature of the stator vibration spectrum is studied. It is concluded that the intensity of the effect of the plate on the fibrous material increases from the centre to the periphery. A formula is proposed for determining plate frequencies taking into account the Doppler effect. The vibration diagnostics of the rotor beats is based on the resonance-demodulation method. Estimating the depth of the amplitude modulation of vibrational acceleration of the stator at the maximum plate frequency with harmonics of the working frequency, it is possible to judge the amount of beating of the rotor plate. A device was developed for vibration diagnostics of the beats of a rotor plate of a disk mill. The developed methods and tools can be used in other industries, for example, in mining and metallurgy. © Published under licence by IOP Publishing Ltd.

An object of research is a vibration of the stator of the knife refining machines and its interrelation with the factors which influences the course of refining among them are technical condition of a plate and change of characteristics of the ground material. The diagnostic model of process of refining is developed and positively approved. The new method of determination of degree of wear of the refining plate of refiners is offered. The new method of management of functioning of the knife refining machines is developed. It is shown that management of work on this indirect indicator is not worse, than the management based on the earlier known diagnostic signs of refiners functioning. The developed method of management is indispensible for the refiners with stepwise regulation of a gap, in a disk-conic refiners and in a dual refiners. Realization of this method under production conditions showed stable characteristics of a gain in degree of refining of a semi-finished fibrous product and decrease in specific power consumption during refining. The developed methods can be used in other branches of industry, for example, mining and metallurgy. © 2019 IOP Publishing Ltd. All rights reserved.

The electron backscatter diffraction method (EBSD) is widely used to study crystallographic orientational relationships of the steel microstructure constituents including bainite. Nevertheless the fine structure of bainite (subunits, plates) is not investigated by this method. In this paper we propose a technique for visualizing of the structure of a bainitic steel near-surface layer using the values of Euler angles obtained by EBSD method. A three-dimensional picture of the bainite fine structure of the HY-TUF steel obtained by the proposed technique is in satisfactory agreement with the data obtained earlier by the atomic force microscopy.

[ES] En el proyecto el alumno estudiará el proceso de desarrollo y validación del diseño de una placa de osteosistesis paramétrica definida a partir de datos antropométricos del paciente con una geometría optimizada mediante métodos numéricos. En este proyecto el modelado geométrico de la placa se realizará con el programa SolidWorks, para posteriormente terminar el diseño son programas de diseño y modelado por elementos finitos propios. El trabajo se centrará en la definición de la forma (optimización mediante MEF) de diseños anteriores, el rediseño y posteriormente en la validación del mismo con datos de comportamiento de diseños anteriores de los que se tiene información. La forma del implante se obtendrá a partir de datos antropométricos de obtenidos de literatura. El diseño se realizará con un programa de diseño, mientras que la validación del mismo se realizará con programa de elementos finitos propio del departamento. Para la validación del diseño, se realizará el mallado del implante, aplicación de condiciones de contorno y cargas. Finalmente, se estudiarán las deformaciones en el modelo y se compararán con modelos experimentales anteriores. PLAN DE TRABAJO (orientativo): 1.- Obtención de la geometría 3D paramétrica a partir de datos bibliográficos. 2.- Definición del diseño con programa de diseño y selección del óptimo. 3.- Mallado y validación mediante elementos finitos de las propiedades mecánicas del diseño con programa de elementos finitos propio del modelo optimizado., [EN] In the project the student will study the process of development and validation of the design of a parametric osteosistesis plate defined from anthropometric data of the patient with a geometry optimized by means of numerical methods. In this project, the geometric modeling of the plate will be carried out with the SolidWorks program, to later finish the design are design programs and modeling by own finite elements. The work will focus on the definition of the form (optimization through MEF) of previous designs, the redesign and later on the validation of the same with behavioral data of previous designs for which information is available. The shape of the implant will be obtained from anthropometric data obtained from literature. The design will be made with a design program, while the validation of the same will be done with the finite element program of the department. For the validation of the design, the meshing of the implant, application of boundary conditions and loads will be carried out. Finally, the deformations in the model will be studied and compared with previous experimental models. WORK PLAN (guidance): 1.- Obtaining parametric 3D geometry from bibliographic data. 2.- Definition of the design with design program and selection of the optimum. 3.- Meshing and validation by finite elements of the mechanical properties of the design with finite element program of the optimized model.

Experimental and numerical studies on shear buckling behaviour of stainless steel plate girders with inclined stiffeners have been carried out in this study. Material properties of the two adopted stainless steel alloys, including austenitic grade EN 1.4301 and duplex grade EN 1.4462 were obtained, and initial geometric imperfections of the cross-sections were determined. Two stainless steel plate girders with inclined stiffeners were tested un-der simply supported conditions. The critical buckling strengths and ultimate shear re-sistances were all obtained and further compared to those of previously tested plate girders with transverse stiffeners only and both transverse and diagonal stiffeners. Elaborated fi-nite element (FE) models developed by means of the FE software package ABAQUS were validated against the obtained experimental results. The validated FE models was subse-quently used to evaluate the influence of the stiffener inclination on the load-carrying ca-pacity of plate girders., Postprint (published version)

Between and Beyond is a series of handbuilt and wheel-thrown ceramic objects which explore intimate queer relationships through the human figure. I assemble slabs of clay to create openings and negative spaces within the sculptures, implying the ways in which the human form also acts as a vessel. The sculptures as well as the figures themselves remain open and vulnerable, literally and metaphorically. The body is depicted through fragmented sections, alluding to the ways in which society and culture break up gender and sexuality into limiting binaries. These intimate, private moments are meant to conjure an imagined future free of limiting gender ideologies and polarizing assumptions about sexuality. My intention is to show multiple figures engaged intimately with each other as well as with themselves in order to point out and elaborate the idea that queerness exists as an ideological framework meant to reject polarization and to embrace the fluid.

[ES] Se aborda el estudio del pandeo de placas y paneles rectangulares, presentes en las estructuras semimoncasco típicas de construcciones aeronáuticas. En primer lugar, se analiza el inicio de pandeo por compresión de dos aproximaciones a un panel aeronáutico: placas con bordes elásticos y placa con un larguerillo rigidizador. Se hace énfasis en la distinción entre modos de pandeos locales y globales, así como en el comportamiento de las distintas zonas del larguerillo. A continuación, se estudia el postpandeo por compresión de una placa teniendo en cuenta diferentes combinaciones en cuanto a la restricción de los bordes laterales, pudiendo así realizar una comparativa y obtener conclusiones. Se finaliza abordando el estudio de postpandeo de paneles por compresión, tanto de un panel simplificado como de un modelo más realista. Para el análisis de cada aspecto, son empleados tanto métodos analíticos como el método de los elementos finitos, basado en el software comercial Abaqus, permitiendo así el contraste de resultados. El postprocesado de gráficas se realiza principalmente por medio del software Gnuplot, a través de una conexión con Matlab., [EN] The study of buckling of rectangular plates, present in the typical aeronautic semi-monocoque structures, is discussed. First, the initial buckling under compression of two approaches to an aeronautical panel is analyzed: plates with elastic edges and a stiffened plate by a single stringer. Emphasis is placed on the distinction between local and global buckling modes, as well as on the behavior of the different areas of the stringer. Next, the postbuckling under compression of a plate is studied taking into account different combinations in terms of the restriction of the lateral edges, thus being able to perform a comparison and obtain conclusions. Finally, the study of post-buckling of panels by compression is approached, both a simplified panel and a more realistic model. For the analysis of each aspect, both analytical methods and the finite element method, based on Abaqus commercial are used, thus allowing the results to be compared. The post-processing of graphs is mainly done by means of the software Gnuplot, through a connection with Matlab.

Hospital meals are important for supporting nutrition goals and the overall hospital experience. The aim of this study was to assess if patients’ perceptions of quality attributes of hot meals were impacted by the type of plate on which the meal was served. Eligible patients selected from medical and/or surgical wards at a 929 bed acute care hospital were randomised to receive hot meals served on either ceramic or disposable plates at eight evening meals. Patients from a multi-centre trial of pre-packaged meals where re-thermalised meals were presented on a variety of colour and shaped disposable plates were included in a second phase. Patient assessment of meal quality was undertaken using the Meal Assessment Tool (MAT)(Hannan-Jones & Capra, 2017) with data collected by interview. In phase one, 137 eligible patients competed the MAT (response 46.8%), with results showing no significant difference in the rating of appearance, quality, expectations or satisfaction when meals were served on disposable or ceramic plates. In phase two data were collected from 6189 patients (response 47.4%). No practical difference in rating of meals was found in relation to colour and sectioning of plates, however a statistical but non-practical difference was found regarding plate shape, with meals served on oblong/rectangular plates rated more positively. Of 3078 comments made concerning the meals, 99 (3.2%) concerned the plates on which the meals were served. This study has shown that quality, appearance and taste of meals, rather than the serving ware are important to patients. Findings suggest that attending to other quality aspects of meals may be far more important than the plate itself, and deserve attention.

The increasing use of Fibre Reinforced Polymers produced by Vacuum Assisted Resin Transfer Molding in civil infrastructure applications leads to the need for an appropriate research data. The VARTM produced structural elements are not limited in dimensions and material properties and typically are slender structures parts of which are susceptible to plate buckling. The latest standards - CUR96 Vezelversterkte kunststoffen in bouwkundige en civieltechnische draagconstructies and JRC Prospect for New Guidance in the Design of FRP – are for a large part based on the research data of pultruded profiles and in terms of design for buckling, focus on the flange / web interaction. The goal of this thesis is to investigate the effect of initial out of plane deformations on buckling of FRP plates produced by VARTM.

This work concerns vibration suppression of plates and plate-like structures by resonant piezoelectric damping, introduced by resistive–inductive shunts. The performance of this type of shunt damping relies on the precise calibration of the shunt frequency, where an important aspect is the ability to account for the energy spill-over from the non-resonant modes, not taken into account by most available calibration methods. A newly proposed calibration procedure includes this residual mode contribution by a quasi-dynamic modal correction, taking both flexibility and inertia effects of the non-resonant modes into account. In this work, this procedure is implemented in a finite element model combining Kirchhoff plate bending kinematics for the host structure and a plane stress assumption for a pair of bonded piezoceramic patches. The established model is verified by comparison with shunt calibrations from benchmark examples in the literature. As demonstrated by frequency response plots and the obtained damping ratios, the resistive–inductive shunt tuning is influenced by the effect of the non-resonant modes and omission may yield a significant detuning of the shunt circuit. Finally, an alternative method for precise evaluation of the effective (or generalized) electromechanical coupling coefficient is derived from the modal electromechanical equations of motion. This results in a new shunt tuning method, based on the effective electromechanical coupling coefficient obtained by the short- and open-circuit frequencies of the coupled piezo-plate structure.

Hlavní náplní mé bakalářské práce byl vlastní návrh bednění mostní konstrukce. Byl vybrán trámový monolitický předpjatý železobetonový most o 3 polích. Pro toto navržené bednění mostní konstrukce jsem provedl zjednodušené statické ověření, které mělo potvrdit únosnost navržené konstrukce. V další části se ve své bakalářské práci zabývám problematikou bednění a to rozdělením systémového bednění podle způsobu použití ve výstavbě. V následujících kapitolách se seznámíme s metodami bednění mostních částí a speciálními metodami, které se při výstavbě mostů v dnešní době používají. Pro lepší představu navržené mostní konstrukce jsem přidal technický popis použitých systémů. Bakalářská práce byla zaměřena na metody a postupy výstavby firmy PERI, spol. s r.o., The main part of my bachelor's thesis introduces my own proposal for the formwork used in bridge construction. I chose a beam, monolitic, prestressed steel-reinforced concrete bridge with three fields. For this particular formwork, I carried out a simplified basic structural check, which is to confirm the load-bearing abilities of the proposed design. The next chapters concentrate on the types of formwork, mainly the different categories of systemic formwork, depending on their intended use in construction. This is then followed by the methods of building bridge formwork, including some unique, bespoke methods used in contemporary bridge construction. To help fully understand my proposed design, I have also included a technical description of the systems used. The bachelor thesis was focused on methods and procedures of construction of company PERI, spol. s r.o., Dopravní fakulta Jana Pernera, Uchazeč stručně seznámil komisi se svou bakalářskou prací. Po prezentaci hlavních výsledků a závěrů bakalářské práce zodpověděl dotazy vedoucího a oponenta bakalářské práce. V diskusi o bakalářské práci stručně zodpověděl všechny dotazy členů komise.

During operations on offshore platforms, lifting of objects (i.e. containers) brings with it dropped object risks. In the occurrence of a dropped object event, production is temporarily interrupted, resulting in unintended costs. Chicago Bridge & Iron Company (CB&I), a leading engineering company in the design of offshore topside structures, is continuously seeking for innovative solutions which minimize costs. To date, protection of vulnerable equipment against dropped objects is provided by conservative stiffened steel plates. An alternative in the form of Sandwich Plate System panels has been researched, as it could potentially reduce costs due to their high failure load to mass ratio. Multiple design thicknesses for simply supported Sandwich Plate System (SPS) beam and plate structures have been considered analytically and numerically. Their masses and failure loads when subjected to quasi-static loads have been compared with a Stiffened Steel Plate (SSP) reference structure. ANSYS, a Finite Element Analysis software package has been used to analyse the force-deflection curves associated with each design and to compare the plots and results with the results obtained analytically. Analytical calculations of the bending moment resistance have shown to be adequate for the beam models under strict assumptions only. For more comprehensive non linear analyses including circular impact loads, an analytical analysis is no longer readily accessible and a numerical analysis is required. While for stiffened steel structures subjected to a line load a ’beam to plate’ simplification assumption is justified, this is not the case for SPS due to its additional transverse stiffness. For beam structures subject to line or circular failure mechanisms, the SSP layout offers a greater yield resistance with respect to its mass than SPS. For plated structures subject to a circular failure mechanism the yield resistance increases more strongly for the SPS type

The behaviour of Carbon Fibre Reinforced Polymers (CFRP) reinforced mild steel isolated plate (strut) under uniform axial compression is not well understood because there is a lack of experimental research. This paper presents experimental results for a series of struts reinforced with CFRP sheets subjected to uniform axial compression. The main parameters examined were the thickness of the steel plates, and the location and the number of the CFRP sheets. Three different thicknesses of steel plates were examined, namely, 2, 3 and 4 mm. The testing program included 21 struts with three different width-to-thickness ratios of 50, 66.7, and 100. The CFRP sheets were adhesively bonded where the fibres were aligned in the longitudinal direction parallel to the direction of the applied force. The results showed that the debonding failure strain in the compression face occurred in the range of 0.3–0.6% for all the composite specimens. It was found that the amount of permanent damage in the composite strut identified by the residual displacement is significantly less than that of the bare strut. Experimental results showed a global increase in strength, energy absorption and ductility for all test specimens where the greatest percentage increases were 452%, 259% and 107%, respectively. The 2 and 3 mm composite specimens showed greater percentage increases than the 4 mm composite specimens due to the relative thickness of the carbon fibre sheets verses steel. All experimental specimens failed by overall buckling, achieving maximum capacity at the end of their elastic range showing that the specimens were successfully bonded and acting as composites within such range. An existing rigid plastic theory considers initial imperfections (defects) was modified and used to predict the response of the struts. Experimental and theoretical curves showed consistency where initial defects controlled the elastic-inelastic behaviour and the load bearing capacity of the strut. In general, sp

Se evaluó el desempeño frente al desgaste abrasivo de láminas antidesgaste y recubrimientos duros aplicados por soldadura eléctrica, utilizando la norma ASTM G-65. Para caracterizar los recubrimientos, a algunos depósitos se les hicieron pruebas de dureza, microscopia óptica y microscopia electrónica de barrido (SEM). Se observó que a medida que aumenta la dureza, aumenta la resistencia al desgaste, pero también se evidenció que no se sigue un patrón de crecimiento lineal. Por lo tanto, la dureza es información que nos puede dar un criterio de selección, pero no puede ser el único factor a la hora de elegir un recubrimiento duro aplicado por soldadura para la protección contra el desgaste abrasivo, ya que hay otros factores que afectan el desgaste, como la distribución y forma de los carburos en el cordón de soldadura. La unión de los recubrimientos con el metal base es muy buena. La dilución con el metal base hace que la dureza del primer pase de soldadura sea menor que la del tercer pase., Performance against abrasive wear was evaluated (in compliance with the ASTM G-65 standard) for both wear plates and hard coatings applied by electric welding. The characterization of the coatings was achieved by using hardness tests, optical microscopy and scanning electron microscopy (SEM). Although it was observed a direct correlation between hardness and wear resistance, a linear growth pattern was not followed. Besides the information from the hardness tests, data regarding the distribution and shape of the carbides in the welding bead are also necessary to choose the hard coating applied by welding, to protect against abrasive wear. Base metal and coatings had satisfactory joint, due to their dilution; the first welding layer had less hardness than the third welding layer.

Die Arbeit beschäftigt sich mit der Notwendigkeit eines Nachweises der Plattenkapazität unter kombinierten Belastungen in der Plattenebene. Umfangreiche numerische Studien unter Nutzung der Finite-Elemente-Methode sind durchgeführt worden. Alle für den Schiffbau relevanten Lastkombinationen und Plattenkonfigurationen wurden hierbei berücksichtigt. Die Studien werden verwendet, um die Versagensmechanik der Platten zu untersuchen und bestehende Nachweise der Plattenkapazität zu bewerten. Um sowohl qualitative als auch quantitative Akzeptanzkriterien zu erfüllen, wird ein neuer Nachweis der Plattenkapazität unter kombinierten Belastungen in der Plattenebene entwickelt. Praktische Anwendungen des Nachweises werden dargestellt., The need for a proof of plate capacity under combined in-plane loads is addressed. An extensive series of numerical studies based on the finite element method is performed covering all load combinations and plating configurations relevant for the shipbuilding industry. These studies are used to investigate the mechanics of plating collapse and to evaluate existing proofs of plate capacity. In order to satisfy both qualitative and quantitative acceptance criteria, a new proof of plate capacity under combined in-plane loads is developed. Practical application of the proof in design is presented.

This paper deals with the shortcomings in current design methods for dynamically loaded composite structures in underwater applications. This is done through an experimental study to evaluate the eigenfrequencies of rectangular plates made from metals as well as composites that are tested in air (dry) and completely submerged under water (fully wetted). The eigenfrequencies are studied using forced vibrations. The test series comprises 19 specimens that are made from various materials including aluminium, steel, glass-fibre, and carbon-fibre with aspect ratios varying from 3.7 to 11.2 and breadth to thickness ratios ranging from 2.7 to 20.5. The test method is based on electro-mechanical excitation by random vibrations as well as stepped sine refinements in the vicinity of the identified eigenfrequency. The results clearly show how differently the specimens are affected by the "added mass" from the water when fully wetted compared to the dry condition. Slender and more lightweight configurations are more profoundly affected by water than heavier and more rigid specimens. The results clearly show that for advanced composite materials and more complex geometries the current rule-of-thumb methods used by the industry today are inadequate in predicting the shift in natural frequency due to the effect of the surrounding water., QC 20160202

The pressure loss of turbulent power law fluid flow between parallel plates has been theoretically analyzed. Using Prandtl mixing length theory and Van Karman similarity hypotheses for turbulent flow, we have derived a new friction factor formula that resembles previous formula for turbulent power law fluid flow in rough pipes. The new formula is also valid for the transition region between smooth and wholly rough wall turbulence.

[EN] The work is based on the study of simple impacts on rectangular plates made of aluminum and/or composite material, with various types of supports and for the second material with several stacking sequences. Analytical studies are to be obtained from the literature, and the numerical from the commercial code Dyna3D., [ES] El trabajo se basa en el estudio de impactos sencillos en placas rectangulares hechas de aluminio y/o material compuesto, con varios tipos de apoyo y para el segundo material con varias secuencias de apilado. Los estudios analíticos se obtendrán de la literatura, y los numéricos del programa comercial Dyna3D.

Structural health monitoring (SHM) is a quickly advancing field of study in civil engineering and recent advances in the field are in stark contrast to where the field started. For example modern technology of wireless sensing systems allowed for easier monitoring of structures, but the challenge of limiting the number of instrumented locations has not been overcome with traditional methods. The potential of alternative methods has only been realized in recent years with the increase of model based approaches. In particular, the use of limited measurements to estimate structural response at all locations is appealing. To accomplish this goal, this work approaches SHM by using a numerical model combined with a linear recursive state estimation algorithm, known as the Kalman Filter, to update the model-based prediction with a limited number of real time measurements taken on the structure. A thorough overview of the contents is given here. The first section introduces the topic of SHM and the goal of SHM. Then the challenges and limitation that face SHM are discussed along with the recent advances that can be used to overcome them. In Section 2, the proposed framework, a Kalman filter approach, is established. First, a finite element model is formulated for plate structures using the Mindlin-Reissner plate theory and then this finite element code is verified by a comparison with a commercial FEA software. Then the state space model of the system is defined for use with the Augmented Kalman Filter (AKF); the AKF approach overcomes the intrinsic challenge of unknown excitations for civil structures. The AKF is then formulated and discussed. For Section 3, using the AKF in numerical simulations are conducted for 5 different cases. The first three cases study the advantages of multi-metric measurements, i.e. strain and acceleration measurements combined, versus single metric measurement, i.e. strain measurement only or acceleration measurement only. Following that, the ne

This MSc thesis addresses the study of buckling and post-buckling of composite plates with elastic restraints at the edges and under any combination of in-plane loading, aiming to solve the plate response in stiffened panel structures. The implemented solutions are based on thin plate theory for mid-plane symmetric plates. The governing equations are solved using a semi-analytical formulation (not closed form) to combine advantages from analytical and numerical analysis. This approach allows to solve most of the typical laminates used in aerospace applications while allowing an improved performance when compared to FE models. The developed formulation relies on eigenbeam functions to approximate the plate behaviour for any combination of arbitrary elastic restrains, with a minimum number of degrees of freedom. This approach has proved to be able to reproduce the buckling mode and load for buckling and the out-of-plane displacement for post-buckling. The results obtained have been verified against FE commercial software package Abaqus and good to excellent agreement has been achieved using a fraction of the computational power. The relation between the ideal torsional springs and stiffeners’ restrain is approximated in order to apply the developed formulations to more practical problems involving stiffened panels. Preliminary verifications show the validity of the proposed approaches and encourages the further development of the solution to achieve a more powerful stiffened panel formulation. Moreover, the developed approaches can be extended to solve other relevant stability phenomena such as global buckling or stiffener crippling. This work is part of a Fokker Aerostructures project to develop an analytical framework for analysis and design of composite stiffened panels with post-buckling capabilities. This framework will facilitate the preliminary design of composite stiffened structures and allow further optimization without requiring the prohibitive computationa, Aerospace Engineering, Aerospace Structures and Computational Mechanics

A mechanical wave is generated as a result of an external force interacting with the well-defined medium and it propagates through that medium transferring energy from one location to another. The ability to generate and control the motion of the mechanical waves through the finite medium opens up the opportunities for creating novel actuation mechanisms not possible before. However, any impedance to the path of these waves, especially in the form of finite boundaries, disperses this energy in the form of reflections. Therefore, it is impractical to achieve steady state traveling waves in finite structures without any reflections. In-spite of all these conditions, is it possible to generate waveforms that travel despite reflections at the boundaries? The work presented in this thesis develops a framework to answer this question by leveraging the dynamics of the finite structures without any active control. Therefore, this work investigates how mechanical waves are developed in finite structures and identifies the factors that influence steady state wave characteristics. Theoretical and experimental analysis is conducted on 1D and 2D structures to realize different type of traveling waves. Owing to the robust characteristics of the piezo-ceramics (PZTs) in vibrational studies, we developed piezo-coupled structures to develop traveling waves through experiments.The results from this study provided the fundamental physics behind the generation of mechanical waves and their propagation through finite mediums. This research will consolidate the outcomes and develop a structural framework that will aid with the design of adaptable structural systems built for the purpose. The present work aims to generate and harness structural traveling waves for various applications.

U radu je određen efektivni modul klizanja kompozitnog panela sa saćastom ispunom. Ovaj elastični koeficijent predstavlja veoma važnu karakteristiku kompozitnih panela, naročito kod kompozitnih konstrukcija koje su izložene uvijanju kao i kombinovanom uvijanju sa savijanjem. Analizirane strukture u ovom radu sastoje se od gornje i donje kompozitne ploče (različitih tipova karbonskih vlakana, T300, AS4 u epoksidnoj matrici) kao i saćaste ispune (HexWeb EC engineered core). Polazeći od klasične teorije lamine, efektivni modul elastičnosti klizanja je određen za svaki sloj u kompozitnoj ploči. Ovi slojevi su spojeni u jedinstveni kompozitni sloj za različita usmerenja vlakana kao i debljine lamina. Elastični koeficijenti saćaste ispune HexWeb središnjeg sloja kompozitnog panela su izračunati koristeći teoriju Master Evans u cilju dobijanja ekvivalentnih vrednosti. Za proveru predloženog pristupa korišćen je metod konačnih elemenata, u cilju dobijanja polja pomeranja, deformacija i napona u kompozitnim pločama i saćastoj ispuni. Dva tipa numeričkih modela su upoređena: početni model, pri čemu su svi slojevi ploče modelirani sa svojim karakteristikama i drugi model kod kojeg su spojeni u jednu celinu sa svojim ekvivalentnim karakteristikama. Zaključeno je da se ekvivalentni metod određivanja modula klizanja kompozitnih panela sa saćastim ispunama može efikasno primeniti u slučajevima kada su gornja i donja kompozitna ploča simetričnog slaganja ili uopšte kvaziizotropna., In the presented paper the effective shear modulus of composite plates with honeycomb core is determined. This elastic coefficient represents one very important property, especially in constructions subjected to torsion and combined bending - torsion. The structures investigated in this research consisted of top and bottom plates (of different types of carbon fibers, T300, AS4 in epoxy matrix) and honeycomb core (HexWeb engineered core). Starting from classical lamination theory, the effective shear modulus of top and bottom plates was determined for each ply in the stack up sequence. These plies were 'lumped' into a single composite layer for different fiber orientations and plies thicknesses. Elastic coefficients for the HexWeb engineered core were obtained using Master and Evans relations for the equivalent properties of honeycomb cores. To verify this approach, finite element method was used to determine the displacement, stress and strain field on composite plates with honeycomb core. Two types of models were compared: the initial model where all the material components, plates and the core were modeled with their intrinsic properties and 'lumped' model with calculated effective elastic coefficients. It was found that the method of effective shear modulus calculation can successfully be used in situations where top and bottom plates are symmetric or quasi isotropic in general.