A combined geological and rock mechanics approach to tunnel face behaviour prediction, based on improved understanding of brittle fracture processes during TBM excavation, was developed to complement empirical design and performance prediction for TBM tunnelling in hard rock geological conditions. A major challenge of this research was combining geological and engineering terminology, methods, and objectives to construct a unified Geomechanical Characterisation Scheme. The goal of this system is to describe the spalling sensitivity of hard, massive, highly stressed crystalline rock, often deformed by tectonic processes. Geological, lab strength testing and TBM machine data were used to quantify the impact of interrelated geological factors, such as mineralogy, grain size, fabric and the heterogeneity of all these factors at micro and macro scale, on spalling sensitivity and to combine these factors within a TBM advance framework. This was achieved by incorporating aspects of geology, tectonics, mineralogy, material strength theory, fracture process theory and induced stresses. Three main approaches were used to verify and calibrate the Geomechanical Characterisation Scheme: geological and TBM data collection from tunnels in massive, highly-stressed rock, interpretation of published mineral-specific investigations of rock yielding processes, and numerical modelling the rock yielding processes in simulated strength tests and the TBM cutting process. The TBM performance investigation was used to identify the mechanism behind the chipping processes and quantify adverse conditions for chipping, including tough rock conditions and stress induced face instability. The literature review was used to identify the critical geological parameters for rock yielding processes and obtain strength and stiffness values for mineral-specific constitutive models. A texture-generating algorithm was developed to create realistic rock analogues and to provide user control over geological characteristics such as mineralogy, grain size and fabric. This methodology was applied to investigate the TBM chipping process to calibrate the Geomechanical Characterisation Scheme. A Chipping Resistance Factor was developed to combine the quantified geological characteristic factors and laboratory strength values to predict conditions with high risk of poor chipping performance arising from tough rock. A Stress-Related Chip Potential Factor was developed to estimate conditions with high risk of advance rate reduction arising from stress-induced face instability. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2008-09-25 23:58:58.071

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Research report on deformation of annual rings is given in the thesis. Aim of the work - to perform an analysis of deformation of annual rings during obsolescence of tree. Tasks of the work - to perform a comparative analysis using borings made in 2004 and 1985 – 1986. To evaluate statistical reliability of deformation of annual rings. Object of the work - trees of Scotch pine (Pinus sylvestris L.). Methods of the work – methods of verification of statistical hypotheses and analysis of variance were used for data processing. Content of the work – verification of hypothesis that annual rings of pine is shrinking during the obsolescence of trees. Results: - difference of annual rings width is statistically reliable at two point of the interval investigated: nearby bark and in the central part of the stem, at the margin where sapwood is converting to heartwood. The shrinking reaches 0.2 mm within 5 annual rings. The biggest influence on shrinking of annual rings has distance of annual rings from the bark and age of tree.

This study examined the role of olfactory and visual cues in host finding of the pine bark beetles Hylastes ater and Hylurgus ligniperda and the burnt pine longhorn beetle Arhopalus ferus. The ultimate aim of this research was to provide new information on attractant and repellent (such as non-host leaf volatiles) stimuli to improve monitoring methods and reduce the attack by wood-boring and bark beetle species. A field trapping trial of visual and olfactory cues near Nelson caught 7842 H. ater, 274,594 H. ligniperda and 16,301 A. ferus adults. There were significant effects of both visual (colour and sihoutte) and olfactory (host and non-host volatiles) cues for all three species. The highest catches were in black (host mimicking), panel flight intercept traps baited with attractant (α-pinene and ethanol) and the lowest in clear or white (non-host mimicking) control traps. The repellent, green leaf volatiles (GLV) ((E)-2-hexen-1-ol & (Z)-3-hexen-1-ol) when present on traps with attractant reduced catches significantly but modestly in H. ater and H. ligniperda, but had no significant effect on A. ferus. A field trial near Christchurch found that GLV applied as a topical repellent halved the number of beetles attacking Pinus radiata logs. This reduction was significant in H. ligniperda, but not quite (P = 0.07) in H. ater. Placing logs among broadleaved plants (natural sources of non-host volatiles) significantly reduced attack of H. ligniperda by about 75% compared to logs in the open, but had no effect on H. ater. Attack by H. ater was found on 4% of 500 P. radiata seedlings in a field trial near Dunedin. Treatment of seedlings with GLV significantly affected the severity and proportion of seedlings attacked by H. ater, compared with insecticide-treated and control seedlings, but the treatment effect was apparently driven by an unexpected direct damaging effect of GLV on the health of seedlings. It is recommended that future research explores the use of non-host volatiles from natural sources that influence host finding in wood–boring and bark beetle species for the protection of plantation forests in New Zealand.

Orientador: Amauri Hassui / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T23:13:39Z (GMT). No. of bitstreams: 1 RossiNeto_Eneas_M.pdf: 13972971 bytes, checksum: 1c7b89f4fdc28248118cde9b4b90db25 (MD5) Previous issue date: 2009 / Resumo: Neste trabalho procurou-se estudar e desenvolver um processo inédito de usinagem para ser implementado na manufatura dos cilindros automotivos, componentes muito importantes utilizados nos motores de automóveis que possuem bloco de alumínio. São poucos e conhecidos os fabricantes do segmento automotivo que fabricam este produto, sendo que, até então, todos utilizavam operação de mandrilamento para usinagem do diâmetro interno da camisa. Entre outras vantagens, este trabalho propõe aumentar a produtividade de maneira significativa, atendendo todas as especificações técnicas do produto. A operação de mandrilamento foi substituída por torneamento interno, utilizando um centro de torneamento com sistema de carga e descarga integrado, ferramentas de corte e dispositivos de fixação especiais e estratégias de usinagem diferenciadas. As camisas para cilindro são fabricadas de ferro fundido cinzento centrifugado, um material extremamente abrasivo que requer cuidados na sua manufatura. Após o desenvolvimento completo do processo e prévios ensaios de usinagem para definição das premissas, utilizou-se uma metodologia objetiva para otimização do processo proposto, realizada no ambiente fabril, considerando todas as variáveis encontradas nas condições reais de produção. Os resultados obtidos mostraram que os insertos de metal duro com cobertura apresentaram um melhor desempenho que os insertos de cerâmica à base de nitreto de silício e de óxido de alumínio na aplicação em estudo, sendo constatado também as melhores condições de corte para o torneamento interno de cilindros automotivos de ferro fundido cinzento centrifugado / Abstract: This investigation describes and shows an unprecedented machining process to be used for manufacturing cylinder liners, which are very important parts used in aluminum engine blocks for automobiles. There are few known companies that manufacture this kind of component, and until now, all of them use a boring process to machine the internal diameter of the cylinder liner. Among other advantages, this investigation intends to increase significantly productivity, while respecting all technical specifications of the product. The boring process was replaced by internal turning, which uses a turning center with load/unload system, special cutting tools and clamp devices, as well as audacious machining strategies. The cylinder liners are made from centrifuged gray cast iron, an extreme abrasive material that needs special care during its machining process. After the complete development of the process and tryouts to define the preliminary data, it has been used an objective methodology to optimize the proposed process, developed on the shop floor, considering all the variables found in real production conditions. The investigation results shown the carbide inserts had better performance than the silicon nitride and aluminum oxide ceramic inserts in this studied application, evidencing the best cutting conditions to internal turning for cylinder liners made of centrifuged gray cast iron / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

This thesis is focused for manufacturing of a gun barrels and his issues. In thesis is involved introducing of the company Česká zbrojovka a.s. and definition of hand fired guns. Written analysis present the state of a technological process and describe an individual phase of manufacturing of the semi-finished product of gun barrel and the following conclusion of a complex manufacturing of a gun barrel from the semi-finished product to the stand, when the gun barrel installed into the gun is. Subsequently are suggested possibly solutions of manufacturing rationalization and possibly purchasing of a new modern CNC machines. In the end is accomplished a technical-economic evaluation, which compares existing and suggesting of the technology.

This master’s thesis deals with design of a headstock for a machine tool. Theoretic part of this thesis provides basic description of a horizontal machine tool. Further it is dedicated to description of a headstock of machines with extensionable work spindle. In a design part firstly optimal variant is chosen by using multicriterial analysis. Necessary calculations were done and chosen variant was developed. Design is realised by 3D CAD model and drawing documentantion.

Diplomová práca je zameraná na riešenie aktuálneho a akutného problému výroby tvarovej hriadele “Hohlwelle” vo firme Vekastool. Tri návrhy riešenia boli sústredené na dokončovaciu operáciu diery 30 H7, z ktorých dva boli priamo odtestované vo firme. Jedna z nich bola návrh a realizácia nového vyvrtávacieho nástroja firmou Ham-Final , ktorá priniesla zníženie nákladov o dve tretiny.

The Master Thesis work this report is based upon has been conducted in cooperation with Svea Teknik AB. Svea Teknik is a consultant firm which is developing parts of a tunnel boring machine on behalf of Atlas Copco. The machine is being developed to mechanically excavate hard rock by fixating itself in the tunnel and then press a large rotating cutter-wheel equipped with disc-cutters against the tunnel wall. The disc-cutters are the tools that are in direct contact with the hard rock and are therefore exposed to extensive wear and needs to be replaced on a regular basis.The purpose of this Master Thesis has been to develop a service equipment that will enable time effective and safe changes of disc-cutters. The disc-cutters have a diameter of 17 inches and weigh about 130 kg. The available space in the tunnel is very limited which puts strict requirements on the size of the service equipment.A specification of requirements was set up based on the background study made in the Master Thesis. Concepts to solve the problem were then generated and evaluated against each other.A concept consisting of a wagon with three slots for disc-cutter transport, a foldable crane with a hoist and a lifting tool adapted to the disc-cutters were chosen for further development. Since the concept was quite extensive the decision was made to focus the work around the lifting tool.By loading new disc-cutters onto the driven wagon together with the foldable crane and the lifting tool, the equipment can be transported past the machine in the tunnel and the crane can then be set up in front of the machine's cutter-wheel. The lifting tool is then lifted by the hoist to enable the disc-cutters in the cutter-wheel to be replaced.The lifting tool consists of two claws that close around the disc-cutter to fixate it geometrically and a counter weight to enable easy positioning of the disc-cutter by hand. The lifting tool is dimensioned according to two different load cases and was verified by FE-analysis.Recommendations for future work and more detailed design were set up. / Examensarbetet denna rapport baseras på, har utförts i samarbete med Svea Teknik AB. Svea Teknik är ett konsultföretag som på uppdrag av Atlas Copco utvecklar delar av en gruvmaskin för tunnelborrning. Maskinen konstrueras för att mekaniskt krossa berget genom att fixera sig i tunnelgången och pressa ett stort skärhjul utrustat med diskformade s.k. kuttrar mot bergväggen samtidigt som skärhjulet roterar. Då kuttrarna är de verktyg som står i direkt kontakt med berget slits de markant och måste bytas ut för service med jämna mellanrum.Detta examensarbete har syftat till att utveckla en serviceutrustning för att möjliggöra snabba och smidiga byten av dessa kuttrar som har en diameter på 17 tum och väger ca 130 kg. Då utrymmet i tunneln är väldigt begränsat finns stora krav på utrustningens storlek.En kravspecifikation, baserad på examensarbetets bakgrundsstudie, utarbetades för att ligga till grund för de genererade koncept som sedan utvärderades gentemot varandra.Efter att ett koncept bestående av en transportvagn med plats för tre kuttrar, en vikbar kran med telfer samt ett specialanpassat kloförsett lyftverktyg hade valts togs beslutet att fokusera arbetet kring lyftverktyget för att begränsa projektets omfång.Genom att lasta nyservade kuttrar på den drivna transportvagnen tillsammans med den hopvikta kranen och lyftverktyget kan den ledas fram förbi maskinen i tunneln och kranen monteras upp framför maskinens skärhjul. Lyftverktyget hängs sedan upp i kranen för att möjliggöra att kuttrar lossas respektive monteras.Lyftverktyget består av två klor som sluts runt kuttern för att fixera den formbetingat samt en motvikt för att för hand kunna ändra rotationen av verktyget kring infästningspunkten. Lyftverktyget dimensionerades utifrån två uppsatta lastfall och verifierades sedan med FEM-analyser

Marine bioeroders, borers, and burrowers can have drastic effects to marine habitats and facilities. By physically altering the structure of marine habitats, these organisms may elicit ecosystem-level effects that cascade through the community. While borer damage is typically restricted to a few substratum types, burrowing isopods in the genus Sphaeroma attack a diversity of substrata in tropical and temperate systems. My dissertation examined how boring sphaeromatid isopods affect coastal habitats (saltmarshes, mangroves) and other estuarine substrata as well as marine structures. I used a combination of lab and mensurative field experiments to quantify the effects of boring by isopods and examine how select factors affect the colonization, hence burrowing damage by isopods. I explored these questions primarily using the temperate boring sphaeromatid, Sphaeroma quoianum, as a model organism. My initial lab experiments quantified the per capita erosion rates of S. quoianum in four commonly attacked estuarine substrata. I found marsh banks and Styrofoam substrata were the most affected per capita. I supplemented this lab experiment with a year-long mensurative field experiment examining how erosion rates differ between marshes infested and uninfested by boring isopods. Marshes infested with isopods eroded 300% faster than uninfested marshes. I further examined the boring effects on Styrofoam floats. I compiled surveys and observations and conducted a short experiment to describe how isopods affect Styrofoam floats used in floating docks. I observed dense colonies of isopods attacking floats and expelling millions of plastic particles in the ocean. The boring effects to simulated Styrofoam floats were also affected by seawater temperature. Burrowing effects in Styrofoam floats exhibited a curvilinear relationship with temperature and peaked around 18°C. These results suggest a 1-2°C increase in water temperature could increase boring effects 5-17% of populations of isopods in Oregon and California bays. To examine the small-scale factors that mediate colonization and boring, I conducted a series of binary choice experiments. I found the presence of conspecifics, biofilm, and shade were important factors influencing colonization. These small scale factors likely explain why isopod attack is focused in some substrata. Finally, to examine the boring effects of tropical isopods in mangroves, I examined the associations between burrowing by S. terebrans and mangrove performance and fecundity. I found negative relationships between boring effects and performance and fecundity in two mangrove species in a restored mangrove stand in Taiwan. Together, these studies elucidate the effects of bioerosive isopods on saltmarshes, mangroves, and marine structures. However, the similar mechanisms involved in bioerosion in other boring species suggest that these results can be used to infer similar effects of other borers. In addition, since many species of sphaeromatid isopods have been introduced, this research shows how the effects of a non-native bioeroder can damage marine facilities and degrade and alter marine habitats. Through biological erosion and thus changing the physical structure of a marine habitat these non-native species can have ecosystem-level effects that cascade throughout the local community.