Análisis mecánico de albañilería arqueológica de adobe bajo cargas de compresión uniaxial: El caso de Huaca de la Luna

This article presents an experimental and numerical study for the mechanical characterization under uniaxial compressive loading of the adobe masonry of one of the most emblematic archaeological complex in Peru, 'Huaca de la Luna' (100-650AD). Compression tests of prisms were carried out with original material brought to the laboratory. For measuring local deformations in the tests, displacement transducers were used which were complemented by a digital image correlation system which allowed a better understanding of the failure mechanism. The tests were then numerically simulated by modelling the masonry as a continuum media. Several approaches were considered concerning the geometrical modelling, namely 2D and 3D simplified models, and 3D refined models based on a photogrammetric reconstruction. The results showed a good approximation between the numerical prediction and the experimental response in all cases. However, the 3D models with irregular geometries seem to reproduce better the cracking pattern observed in the tests.

Classificação e organização de objetos BIM e sua aplicação em modelos 4D&5D

Dissertação de mestrado integrado em Engenharia Civil

Use of LIDAR in landslide investigations: A review

This paper presents a short history of the appraisal of laser scanner technologies in geosciences used for imaging relief by high-resolution digital elevation models (HRDEMs) or 3D models. A general overview of light detection and ranging (LIDAR) techniques applied to landslides is given, followed by a review of different applications of LIDAR for landslide, rockfall and debris-flow. These applications are classified as: (1) Detection and characterization of mass movements; (2) Hazard assessment and susceptibility mapping; (3) Modelling; (4) Monitoring. This review emphasizes how LIDARderived HRDEMs can be used to investigate any type of landslides. It is clear that such HRDEMs are not yet a common tool for landslides investigations, but this technique has opened new domains of applications that still have to be developed.

Stability analysis of the 2007 Chehalis lake landslide based on long-range terrestrial photogrammetry and airborne LIDAR data

On December 4th 2007, a 3-Mm3 landslide occurred along the northwestern shore of Chehalis Lake. The initiation zone is located at the intersection of the main valley slope and the northern sidewall of a prominent gully. The slope failure caused a displacement wave that ran up to 38 m on the opposite shore of the lake. The landslide is temporally associated with a rain-on-snow meteorological event which is thought to have triggered it. This paper describes the Chehalis Lake landslide and presents a comparison of discontinuity orientation datasets obtained using three techniques: field measurements, terrestrial photogrammetric 3D models and an airborne LiDAR digital elevation model to describe the orientation and characteristics of the five discontinuity sets present. The discontinuity orientation data are used to perform kinematic, surface wedge limit equilibrium and three-dimensional distinct element analyses. The kinematic and surface wedge analyses suggest that the location of the slope failure (intersection of the valley slope and a gully wall) has facilitated the development of the unstable rock mass which initiated as a planar sliding failure. Results from the three-dimensional distinct element analyses suggest that the presence, orientation and high persistence of a discontinuity set dipping obliquely to the slope were critical to the development of the landslide and led to a failure mechanism dominated by planar sliding. The three-dimensional distinct element modelling also suggests that the presence of a steeply dipping discontinuity set striking perpendicular to the slope and associated with a fault exerted a significant control on the volume and extent of the failed rock mass but not on the overall stability of the slope.

Cryo-negative staining reveals conformational flexibility within yeast RNA polymerase I.

The structure of the yeast DNA-dependent RNA polymerase I (RNA Pol I), prepared by cryo-negative staining, was studied by electron microscopy. A structural model of the enzyme at a resolution of 1.8 nm was determined from the analysis of isolated molecules and showed an excellent fit with the atomic structure of the RNA Pol II Delta4/7. The high signal-to-noise ratio (SNR) of the stained molecular images revealed a conformational flexibility within the image data set that could be recovered in three-dimensions after implementation of a novel strategy to sort the "open" and "closed" conformations in our heterogeneous data set. This conformational change mapped in the "wall/flap" domain of the second largest subunit (beta-like) and allows a better accessibility of the DNA-binding groove. This displacement of the wall/flap domain could play an important role in the transition between initiation and elongation state of the enzyme. Moreover, a protrusion was apparent in the cryo-negatively stained model, which was absent in the atomic structure and was not detected in previous 3D models of RNA Pol I. This structure could, however, be detected in unstained views of the enzyme obtained from frozen hydrated 2D crystals, indicating that this novel feature is not induced by the staining process. Unexpectedly, negatively charged molybdenum compounds were found to accumulate within the DNA-binding groove, which is best explained by the highly positive electrostatic potential of this region of the molecule, thus, suggesting that the stain distribution reflects the overall surface charge of the molecule.

X-ray microtomography of Larger Foraminifera

X-ray microtomography has become a new tool in earth sciences to obtain non-destructive 3D-image data from geological objects in which variations in mineralogy, chemical composition and/or porosity create sufficient x-ray density contrasts.We present here first, preliminary results of an application to the external and internal morphology of Permian to Recent Larger Foraminifera. We use a SkyScan-1072 high-resolution desk-top micro-CT system. The system has a conical x-ray source with a spot size of about 5µm that runs at 20-100kV, 0-250µA, resulting in a maximal resolution of 5µm. X-ray transmission images are captured by a scintillator coupled via fibre optics to a 1024x1024 pixel 12-bit CCD. The object is placed between the x-ray source and the scintillator on a stub that rotates 360°around its vertical axis in steps as small as 0.24 degrees. Sample size is limited to 2 cm due to the absorption of geologic material for x-rays. The transmission images are back projected using a Feldkamp algorithm into a vertical stack of up to 1000 1Kx1K images that represent horizontal cuts of the object. This calculation takes 2 to several hours on a Double-Processor 2.4GHz PC. The stack of images (.bmp) can be visualized with any 3D-imaging software, used to produce cuts of Larger Foraminifera. Among other applications, the 3D-imaging software furnished by SkyScan can produce 3D-models by defining a threshold density value to distinguish "solid" from "void. Several models with variable threshold values and colors can be imbricated, rotated and cut together. The best results were obtained with microfossils devoid of chamber-filling cements (Permian, Eocene, Recent). However, even slight differences in cement mineralogy/composition can result in surprisingly good x-ray density contrasts.X-ray microtomography may develop into a powerful tool for larger microfossils with a complex internal structure, because it is non-destructive, requires no preparation of the specimens, and produces a true 3D-image data set. We will use these data sets in the future to produce cuts in any direction to compare them with arbitrary cuts of complex microfossils in thin sections. Many groups of benthic and planktonic foraminifera may become more easily determinable in thin section by this way.

Jauhinterien valmistuksen kehittäminen

Diplomityö käsittelee eräälle paperiteollisuuden komponentteja valmistavalle yritykselle tehtyä tutkimusta, jossa tutkittiin erilaisia valmistusmenetelmiä, joilla voidaan valmistaa uudenlaisia jauhinteriä. Diplomityössä ideoitiin erilaisia jauhinteränkonstruktiovaihtoehtoja. Vaihtoehtoja havainnollistamaan piirrettiin jokaisesta ratkaisusta 3D- mallit. Vaihtoehtojen pohjalta päätettiin suoritettavat valmistustestaukset. Työssä suoritettiin valmistustestejä kuitulaserilla, hiilidioksidilaserilla sekä hienosädeplasmalla. Näiden testien perusteella saatiin näkemys siitä, mikä konstruktiovaihto on valmistusteknisesti paras, täyttäen samalla jauhinterälle asetetut vaatimukset. Diplomityön tuloksena syntyi toimiva ja kustannustehokas ratkaisu jauhinterien valmistamiseksi.

Cohesive Elements for Shells

A cohesive element for shell analysis is presented. The element can be used to simulate the initiation and growth of delaminations between stacked, non-coincident layers of shell elements. The procedure to construct the element accounts for the thickness offset by applying the kinematic relations of shell deformation to transform the stiffness and internal force of a zero-thickness cohesive element such that interfacial continuity between the layers is enforced. The procedure is demonstrated by simulating the response and failure of the Mixed Mode Bending test and a skin-stiffener debond specimen. In addition, it is shown that stacks of shell elements can be used to create effective models to predict the inplane and delamination failure modes of thick components. The results indicate that simple shell models can retain many of the necessary predictive attributes of much more complex 3D models while providing the computational efficiency that is necessary for design

Mechanical closing of the paperboard package and the effect of the shape of paperboard package to its manufacturability

The main objective of this thesis was to design a hinge and a closing mechanism for the plastic rim of a paperboard package. Of the hinge and closing mechanisms the 3D-models were designed using SolidWorks program and the functionality of the mechanisms was tested with rapid prototype models. When a mechanism that worked was found, the manufacturability of the mechanisms was tested in an injection molding machine with changeable inserts. Another objective of this thesis was to test the effect of the shape of paperboard package to its manufacturability. The effect of the packages shape was tested with plastic tools made for three different shaped trays. Suggestions for further research were made according to the results of the thesis.

Teollisuuspuhaltimien runkorakenteiden ja siipipyörien suunnittelu

Tämä diplomityö tehtiin Voikkaalla Dust Control Systems Oy:lle. Työ on osa teollisuuspuhaltimien tuotekehitystä yrityksen olemassaolevan puhallinratkaisujen, sekä suunnitteluprosessin kautta. Työn tavoitteena oli tutkia puhaltimen toiminnasta aiheutuvan värähtelyn vaikutusta puhaltimen rakenteisiin nykyisillä puhallinmalleilla, sekä tutkia eri rakenneratkaisujen käyttöä yrityksen normaalista tuotelinjasta suuremmilla puhaltimilla. Työ toteutettiin kahden toteutuneen puhallinprojektin yhteydessä, joiden rakenteellisia ominaisuuksia pyrittiin arvioimaan normaalin suunnitteluprosessin ohella puhallinkomponenttien mitoituksen suhteen. Molemmat projektit olivat yrityksen mittakaavassa huomattavan suuria sekä suunnittelultaan haastavia, joten ne sopivat diplomityön toteutukseen hyvin. Suunnittelussa käytettiin FE-mallinnukseen Femap ja COMSOL-ohjelmistoja, sekä värähtelyn simulointiin yliopistolla kehitettyä RoBeDyn – laskentaohjelmaa. Työn aikana todettiin, että tarkempi FE-mallinnus yrityksen valmiista 3D-malleista on varsin hankala toteuttaa ja vaatisi mallien suunnittelun erityisesti lujuuslaskentaa varten. Laskennassa päädyttiin käyttämään yksinkertaistettuja malleja, joiden avulla saatiin johdonmukaisia arvioita puhaltimien toiminnasta eri materiaalivahvuuksilla. Käytännössä tuloksien oikeellisuutta päästään arvioimaan kesällä 2015 puhaltimien valmistuttua.

Modeling of allergen proteins found in sea food products

Shellfish are a source of food allergens, and their consumption is the cause of severe allergic reactions in humans. Tropomyosins, a family of muscle proteins, have been identified as the major allergens in shellfish and mollusks species. Nevertheless, few experimentally determined three-dimensional structures are available in the Protein Data Base (PDB). In this study, 3D models of several homologous of tropomyosins present in marine shellfish and mollusk species (Chaf 1, Met e1, Hom a1, Per v1, and Pen a1) were constructed, validated, and their immunoglobulin E binding epitopes were identified using bioinformatics tools. All protein models for these allergens consisted of long alpha-helices. Chaf 1, Met e1, and Hom a1 had six conserved regions with sequence similarities to known epitopes, whereas Per v1 and Pen a1 contained only one. Lipophilic potentials of identified epitopes revealed a high propensity of hydrophobic amino acids in the immunoglobulin E binding site. This information could be useful to design tropomyosin-specific immunotherapy for sea food allergies.

Sähkömekaanisen turvalaakerirakenteen suunnittelu

Turvalaakereita käytetään suojaamaan aktiivisia magneettilaakereita vikatilanteiden tapahtuessa. Tässä kandidaatintyössä suunniteltiin erilaisia ratkaisuja toteuttaa turvalaakerin toiminta sähkömekaanisella toimilaitteella. Työn tarkoituksena oli löytää uusia tapoja toteuttaa turvalaakerin rakenne. Uusilla ratkaisuilla poistettiin turvalaakereille ominaisia ongelmia. Suunnittelussa käytettiin perinteisiä koneensuunnittelun menetelmiä. Menetelmien tarkoitus oli mahdollistaa järjestelmällinen suunnittelu. Tässä työssä myös kirjallisuuskatsaus toimi yhtenä suunnittelun vaiheena. Tuloksiksi saatiin hahmotelmia ja 3D-malleja. Tulokset poikkesivat tavanomaisista turvalaakereiden rakenteista. Tuloksissa huomioitiin, että tässä työssä ei suunnitella valmista tuotetta. Suunniteltujen turvalaakereiden toiminta perustui mekanismeihin, jotka toivat mukanaan uusia ominaisuuksia. Sähkömekaanisen toimilaitteen sijoittaminen mekanismeihin oli kuitenkin vaikeaa. Työn tulokset avasivat uusia näkökulmia turvalaakerirakenteiden jatkokehittämiseen.

Hakeperävaunun rungon esikorotuksen määritys

Hakeperävaunun rungon esikorotuksen suuruutta laskennallisesti ei ollut aiemmin määritet-ty Konepaja Antti Ranta Oy:ssä. Hakeperävaunun runko on valmistettu teräksestä. Tutki-muksessa luoduilla laskentamalleilla selvitettiin viisiakselisen hakeperävaunun rungon pys-tysuuntainen taipuma kuormitettuna. Tutkimus suoritettiin laskemalla hakeperävaunun pystysuuntainen siirtymä 42 tonnin ja 36 tonnin kokonaismassojen kuormituksilla hakeperävaunun rungon pituuden suhteen. Käsin-laskentamenetelmä on tässä tutkimuksessa englannin kieliseltä nimeltään conjugate beam method, suoraan käännettynä konjugaattipalkkimenetelmä. FE-analyysia sovellettiin kah-della eri laskentamallilla; käsinlaskentaa vertailevalla ja todellista hakeperävaunun runkoa vertailevilla FE-analyyseilla. Tutkimuksessa käytettyjen eri laskentatapojen tulokset vastasivat toisiaan sekä 42 tonnin että 36 tonnin kokonaismassojen kuormituksilla. Esikorotus määritettiin 42 tonnin koko-naismassalla kuormitetun todellista hakeperävaunun runkoa vastaavan 3D-mallin pysty-suuntaisesta taipumasta, josta luotiin esikorotettu hakeperävaunun rungon 3D-malli. Tutkimuksessa kehitettyjä laskentamalleja voidaan tulevaisuudessa käyttää yrityksen tuo-tekehityksessä. Esikorotuksella voidaan kompensoida pystysuuntaista taipumaa, jos esiko-rotuksesta ei ole haittaa itse rakenteelle.

Automatic Structure Generation using Genetic Programming and Fractal Geometry

Three dimensional model design is a well-known and studied field, with numerous real-world applications. However, the manual construction of these models can often be time-consuming to the average user, despite the advantages o ffered through computational advances. This thesis presents an approach to the design of 3D structures using evolutionary computation and L-systems, which involves the automated production of such designs using a strict set of fitness functions. These functions focus on the geometric properties of the models produced, as well as their quantifiable aesthetic value - a topic which has not been widely investigated with respect to 3D models. New extensions to existing aesthetic measures are discussed and implemented in the presented system in order to produce designs which are visually pleasing. The system itself facilitates the construction of models requiring minimal user initialization and no user-based feedback throughout the evolutionary cycle. The genetic programming evolved models are shown to satisfy multiple criteria, conveying a relationship between their assigned aesthetic value and their perceived aesthetic value. Exploration into the applicability and e ffectiveness of a multi-objective approach to the problem is also presented, with a focus on both performance and visual results. Although subjective, these results o er insight into future applications and study in the fi eld of computational aesthetics and automated structure design.

Passive Solar Building Design Using Genetic Programming

Passive solar building design is the process of designing a building while considering sunlight exposure for receiving heat in winter and rejecting heat in summer. The main goal of a passive solar building design is to remove or reduce the need of mechanical and electrical systems for cooling and heating, and therefore saving energy costs and reducing environmental impact. This research will use evolutionary computation to design passive solar buildings. Evolutionary design is used in many research projects to build 3D models for structures automatically. In this research, we use a mixture of split grammar and string-rewriting for generating new 3D structures. To evaluate energy costs, the EnergyPlus system is used. This is a comprehensive building energy simulation system, which will be used alongside the genetic programming system. In addition, genetic programming will also consider other design and geometry characteristics of the building as search objectives, for example, window placement, building shape, size, and complexity. In passive solar designs, reducing energy that is needed for cooling and heating are two objectives of interest. Experiments show that smaller buildings with no windows and skylights are the most energy efficient models. Window heat gain is another objective used to encourage models to have windows. In addition, window and volume based objectives are tried. To examine the impact of environment on designs, experiments are run on five different geographic locations. Also, both single floor models and multi-floor models are examined in this research. According to the experiments, solutions from the experiments were consistent with respect to materials, sizes, and appearance, and satisfied problem constraints in all instances.