Evaluation of Gap-Graded Asphalt Concrete Mixtures Part II: Statistical Design and Analysis, HR-157, 1973

This report presents the results of a comparative laboratory study between well- and gap-graded aggregates used in asphalt concrete paving mixtures. A total of 424 batches of asphalt concrete mixtures and 3, 960 Marshall and Hveem specimens were examined. The main thrust of the statistical analysis conducted in this experiment was in the calibration study and in Part I of the experiment. In the former study, the compaction procedure between the Iowa State University Lab and the Iowa Highway Commission Lab was calibrated. By an analysis of the errors associated with the measurements we were able to separate the "preparation" and "determination" errors for both laboratories as well as develop the calibration curve which describes the relationship between the compaction procedures at the two labs. In Part I, the use of a fractional factorial design in a split plot experiment in measuring the effect of several factors on asphalt concrete strength and weight was exhibited. Also, the use of half normal plotting techniques for indicating significant factors and interactions and for estimating errors in experiments with only a limited number of observations was outlined,

FM127: Systemic metal ion levels in patients with modular neck total hip arthroplasties: a prospective cohort study

There is increasing evidence that modular neck stems are prone to corrosion-related complications. Recent studies showed elevated metal ions levels and occasional pseudotumor formation in patients with such implants. The purpose of this study was to compare systemic metal-ion levels in patients after primary THA with modular neck stems to those of patients after non-modular implants. To our knowledge, this is the first cohort study including a control group, THA without CoCr heads and dry-assembled neck-stem connections. Methods: 50 patients after THA at a minimum follow-up of 1 year have been selected for the study. Patients with multiple prosthesis or other implants have been deselected. All received a cementless SPS stem from Symbios (Ti6Al4V). 40 patients have the modular neck (CoCr) version and 10 a monobloc version. All bearings were either ceramic-ceramic or ceramic-polyethylene to minimize other sources of CoCr ion release. In the modular group, the neck was chosen pre-operatively based on a 3D planning, allowing for a dry assembly of the stem and neck on the back table before implantation. A plasma system coupled to mass spectrometry was used for a complete elementary quantification in blood and serum separately. Clinical outcome was measured using the Oxford Hip Score. Results : Complete data sets of 29 patients (24 in the modular neck-group (10male, mean age 63y, 35-84y) and 5 in the monobloc-group (3 male, 69 y, 51-83y) are available to date. Mean Co blood levels were .95 ug/L (.14-12.4) in the modular group vs .27 ug/L (.10-.73) in the monobloc group (p=.2). Respective values for Cr were significantly higher in the modular group (.99 g/L; range .75-1.21) compared to those in the monobloc group (.74 g/L ;.62-.86; p=.001). No significant difference was found when comparing serum levels. 5/24 patients had Co levels above 1 g/L (12/24 for Cr), which is by some considered as a relevant elevation. The maximum Co level was measured in an asymptomatic patient. The Oxford Hip Scores were similar in both groups. Conclusion: Cr levels were significantly elevated in the modular neck group compared to those in the monobloc group. 1/24 patients with a modular prosthesis exhibited Co levels, which are beyond the threshold accepted even for metal-on-metal bearing couples. These results have contributed to our decision to abandon the use of modular neck stems. Routine follow-up including annual measurements of systemic CoCr concentrations should be considered.

New stratigraphic data from the Lower Penninic between the Adula nappe and the Gotthard massif and consequences for the tectonics and the paleogeography of the Central Alps

New stratigraphic data along a profile from the Helvetic Gotthard massif to the remnants of the North Penninic basin in eastern Ticino and Graubunden are presented. The stratigraphic record together with existing geochemical and structural data, motivate a new interpretation of the fossil European distal margin. We introduce a new group of Triassic facies, the North-Penninic-Triassic (NPT), which is characterised by the Ladinian ``dolomie bicolori''. The NPT was located in-between the Brianconnais carbonate platform and the Helvetic lands. The observed horizontal transition, coupled with the stratigraphic superposition of a Helvetic Liassic on a Briaconnais Triassic in the Luzzone-Terri nappe, links, prior to Jurassic rifting, the Brianconnais paleogeographic domain at the Helvetic margin, south of the Gotthard. Our observations suggest that the Jurassic rifting separated the Brianconnais domain from the Helvetic margin by complex and protracted extension. The syn-rift stratigraphic record in the Adula nappe and surroundings suggests the presence of a diffuse rising area with only moderately subsiding basins above a thinned continental and proto-oceanic crust. Strong subsidence occurred in a second phase following protracted extension and the resulting delamination of the rising area. The stratigraphic coherency in the Adula's Mesozoic questions the idea of a lithospheric m lange in the eclogitic Adula nappe, which is more likely to be a coherent alpine tectonic unit. The structural and stratigraphic observations in the Piz Terri-Lunschania zone suggest the activity of syn-rift detachments. During the alpine collision these faults are reactivated (and inverted) and played a major role in allowing the Adula subduction, the ``Penninic Thrust'' above it and in creating the structural complexity of the Central Alps. (C) 2012 Elsevier B.V. All rights reserved.

Laboratory Investigation of Bridge Strip Seal Joint Termination Details, SPR RB08-014, 2016

Bridge expansion joints, if not properly designed, constructed, and maintained, often lead to the deterioration of critical substructure elements. Strip seal expansion joints consisting of a steel extrusion and neoprene gland are one type of expansion joint and are commonly used by the Iowa Department of Transportation (DOT). Strip seal expansion joints are susceptible to tears and pull outs that allow water, chlorides, and debris to infiltrate the joint, and subsequently the bearings below. One area of the strip seal that is particularly problematic is where it terminates at the interface between the deck and the barrier rail. The Iowa DOT has noted that the initial construction quality of the current strip seal termination detail is not satisfactory, nor ideal, and a need exists for re-evaluation and possibly re-design of this detail. Desirable qualities of a strip seal termination detail provide a seal that is simple and fast to construct, facilitate quick gland removal and installation, and provide a reliable, durable barrier to prevent chloride-contaminated water from reaching the substructure. To meet the objectives of this research project, several strip seal termination details were evaluated in the laboratory. Alternate termination details may not only function better than the current Iowa DOT standard, but are also less complicated to construct, facilitating better quality control. However, uncertainties still exist regarding the long-term effects of using straight-through details, with or without the dogleg, that could not be answered in the laboratory in the short time frame of the research project.

Structural, metamorphic and geochronological relations between the Zanskar Shear Zone and the Miyar Shear Zone (NW Indian Himalaya): Evidence for two distinct tectonic structures and implications for the evolution of the High Himalayan Crystalline of Zanskar

The geologic structures and metamorphic zonation of the northwestern Indian Himalaya contrast significantly with those in the central and eastern parts of the range, where the high-grade metamorphic rocks of the High Himalayan Crystalline (HHC) thrust southward over the weakly metamorphosed sediments of the Lesser Himalaya along the Main Central Thrust (MCT). Indeed, the hanging wall of the MCT in the NW Himalaya mainly consists of the greenschist facies metasediments of the Chamba zone, whereas HHC high-grade rocks are exposed more internally in the range as a large-scale dome called the Gianbul dome. This Gianbul dome is bounded by two oppositely directed shear zones, the NE-dipping Zanskar Shear Zone (ZSZ) on the northern flank and the SW-dipping Miyar Shear Zone (MSZ) on the southern limb. Current models for the emplacement of the HHC in NW India as a dome structure differ mainly in terms of the roles played by both the ZSZ and the MSZ during the tectonothermal evolution of the HHC. In both the channel flow model and wedge extrusion model, the ZSZ acts as a backstop normal fault along which the high-grade metamorphic rocks of the HHC of Zanskar are exhumed. In contrast, the recently proposed tectonic wedging model argues that the ZSZ and the MSZ correspond to one single detachment system that operates as a subhorizontal backthrust off of the MCT. Thus, the kinematic evolution of the two shear zones, the ZSZ and the MSZ, and their structural, metamorphic and chronological relations appear to be diagnostic features for discriminating the different models. In this paper, structural, metamorphic and geochronological data demonstrate that the MSZ and the ZSZ experienced two distinct kinematic evolutions. As such, the data presented in this paper rule out the hypothesis that the MSZ and the ZSZ constitute one single detachment system, as postulated by the tectonic wedging model. Structural, metamorphic and geochronological data are used to present an alternative tectonic model for the large-scale doming in the NW Indian Himalaya involving early NE-directed tectonics, weakness in the upper crust, reduced erosion at the orogenic front and rapid exhumation along both the ZSZ and the MSZ.

Performance Characteristics of an Axial-Flux Solid-Rotor-Core Induction Motor

The integration of electric motors and industrial appliances such as pumps, fans, and compressors is rapidly increasing. For instance, the integration of an electric motor and a centrifugal pump provides cost savings and improved performance characteristics. Material cost savings are achieved when an electric motor is integrated into the shaft of a centrifugal pump, and the motor utilizes the bearings of the pump. This arrangement leads to a smaller configuration that occupies less floor space. The performance characteristics of a pump drive can be improved by using the variable-speed technology. This enables the full speed control of the drive and the absence of a mechanical gearbox and couplers. When using rotational speeds higher than those that can be directly achieved by the network frequency the structure of the rotor has to be mechanically durable. In this thesis the performance characteristics of an axial-flux solid-rotor-core induction motor are determined. The motor studied is a one-rotor-one-stator axial-flux induction motor, and thus, there is only one air-gap between the rotor and the stator. The motor was designed for higher rotational speeds, and therefore a good mechanical strength of the solid-rotor-core rotor is required to withstand the mechanical stresses. The construction of the rotor and the high rotational speeds together produce a feature, which is not typical of traditional induction motors: the dominating loss component of the motor is the rotor eddy current loss. In the case of a typical industrial induction motor instead the dominating loss component is the stator copper loss. In this thesis, several methods to decrease the rotor eddy current losses in the case of axial-flux induction motors are presented. A prototype motor with 45 kW output power at 6000 min-1 was designed and constructed for ascertaining the results obtained from the numerical FEM calculations. In general, this thesis concentrates on the methods for improving the electromagnetic properties of an axial-flux solid-rotor-core induction motor and examines the methods for decreasing the harmonic eddy currents of the rotor. The target is to improve the efficiency of the motor and to reach the efficiency standard of the present-day industrial induction motors equipped with laminated rotors.

Nappe geometry in the Western Swiss Alps

Detailed geological mapping during the last 20 years in the Western Swiss Alps has shown clearly that most of the lower basement nappes are fold nappes possessing normal and inverted limbs. Moreover their cores are made of strongly deformed gneisses indicating that important ductile strain took place during the formation of the fold nappes. It is therefore probably wrong to imagine deep basement nappes as rigid slices as often actually claimed, especially when interpreting seismic profiles. True `brittle type' thrust nappes involving basement rocks only occur in the internal and upper parts of the belt. Cover nappes, on the contrary, are in most parts of the Alpine belt thrust sheets following more or less the rules of thin-skinned tectonics. Many basement fold nappes lost part of their sedimentary cover during or just before their formation, by decollement along ductile horizons. The result is that many cover thrust nappes in the external part of the Alps are directly related to their original basement fold nappes.

Aktiivisten magneettilaakereiden tilasäädön mallinnus ja simulointi

Aktiivisten magneettilaakereiden avulla on mahdollista kannatella ferromagneettisia kappaleita, kuten sähkökoneiden roottoreita, ilman fyysistä kontaktia. Magneettilaakerit tarjoavat monia etuja, kuten esimerkiksi kitkattomuuden, verrattuina perinteisiin mekaanisiin laakereihin. Nämä edut vielä korostuvat suurnopeuskäytöissä, jotka ovat magneettilaakereiden pääasiallisia käyttökohteita. Tässä työssä esitellään magneettilaakereihin liittyvät erusteoriat ja niiden sovellustavat. Tämän jälkeen tarkastellaanmagneettilaakereiden kanssa käytettäviä säätöratkaisuja ja esitetään niille soveltuvat viritysmenetelmät. Teorioiden pohjalta rakennetaan täydellinen magneettilaakerijärjestelmän simulointimalli säätöratkaisuineen ja suoritetaan järjestelmän toimintaa kuvaavia simulointeja. Simuloinneissa saadut tulokset pyritään vielä varmentamaan suorittamalla mittauksia koelaitteistolla ja vertaamalla saatuja tuloksia keskenään.

Tectonic and metamorphic evolution of the Central Himalayan Domain in Southeast Zanskar (Kashmir, India)

La région du Zanskar, étudiée dans le cadre de ce travail, se situe au passage entre deux domaines himalayens fortement contrastés, la Séquence Cristalline du Haut Himalaya (HHCS), composée de roches métamorphiques et l'Himalaya Tethysien (TH), composé de séries sédimentaires. La transition entre ces deux domaines est marquée par une structure tectonique majeure, la Zone de Cisaillement du Zanskar (ZSZ), au sein de laquelle on observe une augmentation extrêmement rapide, mais néanmoins graduelle, du degré du métamorphisme entre le TH et le HHCS. Il a été établi que le HHCS n'est autre que l'équivalent métamorphique des séries sédimentaires de la base du TH. C'est principalement lors d'un épisode de mise en place de nappes à vergence sudouest, entre l'Eocène moyen et l'Oligocène, que les séries sédimentaires de la base du TH ont été entraînées en profondeur où elles ont subi un métamorphisme de type barrovien. Au début du Miocène, le HHCS à été exhumé en direction du sud-ouest sous forme d'une grande nappe, délimitée a sa base par le MCT (principal chevauchement central) et à son sommet par la Zone de Cisaillement du Zanskar. L'ensemble des zones barroviennes, de la zone à biotite jusqu'à la zone à disthène, a été cisaillée par les mouvements en faille normale au sommet du HHCS et se retrouve actuellement sur une épaisseur d'environ 1 kilomètre au sein de la ZSZ. La décompression associée à l'exhumation du HHCS a provoqué la fusion partielle d'une partie du HHCS et a donné naissance à des magmas de composition leucogranitiques. Grâce à la géothermobarometrie, et connaissant la géométrie de la ZSZ, il nous a été possible de déterminer que le rejet le long de cette structure d'extension est d'au moins 35?9 kilomètres. Une série d'arguments nous permet cependant de suggérer que ce rejet aurait pu être encore bien plus important (~100km). Les données géochronologiques nous permettent de contraindre la durée des mouvements d'extension le long de la ZSZ à 2.4?0.2 Ma entre 22.2?0.2 Ma et 19.8?0.1 Ma. Ce travail apporte de nouvelles données sur les processus métamorphiques, magmatiques et tectoniques liés aux phénomènes d'extension syn-orogeniques.<br/><br/>The southeastern part of Zanskar is located at the transition between two major Himalayan domains of contrasting metamorphic grade, the High Himalayan Crystalline Sequence (HHCS) and the Tethyan Himalaya (TH). The transition between the TH and the HHCS is marked by a very rapid, although perfectly gradual, decrease in metamorphic grade, which coincides with a major tectonic structure, the Zanskar Shear Zone (ZSZ). It is now an established fact that the relation between the HHCS and the TH is not one of basement-cover type, but that the metasedimentary series of the HHCS represent the metamorphic equivalent of the lowermost sedimentary series of the TH. This transformation of sedimentary series into metamorphic rocks, and hence the differentiation between the TH and the HHCS, is the consequence of crustal thickening associated to the formation of large scale southwest vergent nappes within the Tethyan Himalaya sedimentary series. This, Middle Eocene to Oligocene, episode of crustal thickening and associated Barrovian metamorphism is followed, shortly after, by the exhumation of the HHCS as a, large scale, south-west vergent, nappe. Foreword The exhumation of the HHCS nappe is marked by the activation of two contemporaneous structures, the Main Central Thrust at its base and the Zanskar Shear Zone at its top. Extensional movements along the ZSZ, caused the Barrovian biotite to the kyanite zones to be sheared and constricted within the ~1 km thick shear zone. Decompression associated with the exhumation of the HHCS induced the formation of leucogranitic magmas through vapour-absent partial melting of the highest-grade rocks. The combination of geothermobarometric data with a geometric model of the ZSZ allowed us to constrain the net slip at the top of the HHCS to be at least 35?9 kilometres. A set of arguments however suggests that these movements might have been much more important (~ 100 km). Geochronological data coupled with structural observations constrain the duration of ductile shearing along the ZSZ to 2.4?0.2 Ma between 22.2?0.2 Ma and 19.8?0.1 Ma. This study also addresses the consequences of synorogenic extension on the metamorphic, tectonic and magmatic evolution of the upper parts of the High Himalayan Crystalline Sequence.

Experimental and Numerical Analysis of Different Volutes in a Centrifugal Compressor

In a centrifugal compressor the flow around the diffuser is collected and led to the pipe system by a spiral-shaped volute. In this study a single-stage centrifugal compressor with three different volutes is investigated. The compressorwas first equipped with the original volute, the cross-section of which was a combination of a rectangle and semi-circle. Next a new volute with a fully circular cross-section was designed and manufactured. Finally, the circular volute wasmodified by rounding the tongue and smoothing the tongue area. The overall performance of the compressor as well as the static pressure distribution after the impeller and on the volute surface were measured. The flow entering the volute was measured using a three-hole Cobra-probe, and flow visualisations were carriedout in the exit cone of the volute. In addition, the radial force acting on theimpeller was measured using magnetic bearings. The complete compressor with thecircular volute (inlet pipe, full impeller, diffuser, volute and outlet pipe) was also modelled using computational fluid dynamics (CFD). A fully 3-D viscous flow was solved using a Navier-Stokes solver, Finflo, developed at Helsinki University of Technology. Chien's k-e model was used to take account of the turbulence. The differences observed in the performance of the different volutes were quite small. The biggest differences were at low speeds and high volume flows,i.e. when the flow entered the volute most radially. In this operating regime the efficiency of the compressor with the modified circular volute was about two percentage points higher than with the other volutes. Also, according to the Cobra-probe measurements and flow visualisations, the modified circular volute performed better than the other volutes in this operating area. The circumferential static pressure distribution in the volute showed increases at low flow, constant distribution at the design flow and decrease at high flow. The non-uniform static pressure distribution of the volute was transmitted backwards across the vaneless diffuser and observed at the impeller exit. At low volume flow a strong two-wave pattern developed into the static pressure distribution at the impeller exit due to the response of the impeller to the non-uniformity of pressure. The radial force of the impeller was the greatest at the choke limit, the smallest atthe design flow, and moderate at low flow. At low flow the force increase was quite mild, whereas the increase at high flow was rapid. Thus, the non-uniformityof pressure and the force related to it are strong especially at high flow. Theforce caused by the modified circular volute was weaker at choke and more symmetric as a function of the volume flow than the force caused by the other volutes.

On the Reversed Brayton Cycle with High Speed Machinery

This work was carried out in the laboratory of Fluid Dynamics, at Lappeenranta University of Technology during the years 1991-1996. The research was a part of larger high speed technology development research. First, there was the idea of making high speed machinery applications with the Brayton cycle. There was a clear need to deepen theknowledge of the cycle itself and to make a new approach in the field of the research. Also, the removal of water from the humid air seemed very interesting. The goal of this work was to study methods of designing high speed machinery to the reversed Brayton cycle, from theoretical principles to practical applications. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. A new calculation method for the Braytoncycle is developed. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. Also, the influence of calculating the process with actual, achievable process equipment efficiencies is essential for the development of the future machinery. The above theoretical calculations are confirmed with two different laboratory prototypes. The high speed machinery concept allows one to build an application with only one rotating shaft including all the major parts: the high speed motor, the compressor and the turbine wheel. The use of oil free bearings and high rotational speed outlines give several advantages compared to conventional machineries: light weight, compact structure, safe operation andhigher efficiency at a large operational region. There are always problems whentheory is applied to practice. The calibrations of pressure, temperature and humidity probes were made with care but still measurable errors were not negligible. Several different separators were examined and in all cases the content of the separated water was not exact. Due to the compact sizes and structures of the prototypes, the process measurement was slightly difficult. The experimental results agree well with the theoretical calculations. These experiments prove the operation of the process and lay a ground for the further development. The results of this work give very promising possibilities for the design of new, commercially competitive applications that use high speed machinery and the reversed Brayton cycle.

Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula Mediterranean Sea).

The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almería. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area.

Sähkömoottorin rakenteen analysointi tärisevässä käytössä

Tämän työn tavoitteena oli suunnitella esimerkkirakenne vaikeisiin olosuhteisiin tarkoitetusta sähkömoottorista. Ensisijaisesti tarkasteltavia osia sähkömoottorin rakenteessa olivat roottoriakseli, laakerointi sekä laakerikilvet. Laakeroinnista tarkasteltiin laakerivaurioiden syntymistä, tarvittavaa esijännitysvoimaa sekä jälkivoitelua. Lisäksi momenttiakselista tarkasteltiin sen vääntövärähtelyominaisuuksia sekä rungosta ja laakerikilvistä niiden jännityksiä B5-kiinnitysasennossa, eli laippakiinnityksessä. Työstä pyrittiin tekemään suunnitteluohje vastaavanlaisiin suunnittelutehtäviin. Tämän työn kirjallisessa osassa tarkasteltiin oikosulkumoottorin rakennetta ja laakerointia, josta perehdyttiin erityisesti erilaisiin kuormitustilanteisiin, voiteluun sekä kestoiänlaskentaan. Lisäksi tarkasteltiin roottoridynamiikkaa ja ominaismuotojen laskentaa. Kokonaisen roottorin, sisältäen roottoriakselin, –levypaketin, laakeroinnin ja ylikuormitussuojan, pienimmäksi ominaistaajuudeksi saatiin 62,1 Hz:ä, joka oli kuitenkin lähes kaksinkertainen verrattaessa roottorin käyntinopeuteen (33,3 Hz:ä). On siis varmaa, että roottorin kestoikä ei heikkene sen ominaistaajuuksien aiheuttamasta resonanssista. Pelkän roottoriakselin pienimmäksi ominaistaajuudeksi saatiin 448,0 Hz:ä. Verrattaessa tätä taajuutta roottorin käyntinopeuteen nähtiin, että roottoriakselin ominaistaajuuksien puolesta rakenne oli selvästi alikriittinen. Tarkasteltaessa roottoriakselin vääntövärähtelyn ominaistaajuutta 12,6 Hz:ä nähtiin, että se oli pienempi kuin moottorin pyörimisnopeus. Tämä ei kuitenkaan ollut moottorin kestoiän kannalta vakavaa. Koska todellisista sähkömoottorin käyttöolosuhteista ei ollut tarkkaa tietoa, tutkittiin laakeroinnin kestoikää kahdessa ääriolosuhteessa, joko moottoriin kohdistuva tärinä oli kokoajan suurin mahdollinen tunnettu tai tärinää ei ollut ollenkaan. Todellinen tilanne on jossakin näiden kahden ääriolosuhteen välissä. Oli kuitenkin varmaa, että tarkasteltava rakenne kestää halutun kestoiän eli 10000 tuntia laakeroinnin puolesta. Laakerikilpien ominaistaajuudet olivat korkeita eikä niillä ollut vaikutusta rakenteen kestoikään. Laakerikilpien korkeat ominaistaajuudet johtuivat niiden jäykästä rakenteesta ja suuresta materiaalipaksuudesta. Tarkasteltaessa momenttiakselin vääntövärähtelyn ominaistaajuutta 7,2 Hz:ä nähtiin, että se oli pienempi kuin moottorin pyörimisnopeus. Tämä ei kuitenkaan ollut moottorin kestoiän kannalta vakavaa, jos ominaistaajuus ja sen kerrannaiset ohitettaisiin sähkömoottorin käytössä hetkellisesti eikä moottoria käytettäisi vääntövärähtelyn taajuudella. Tarkasteltaessa B5-asennon jännityksiä nähdään, että ne kasvoivat rungon ja laakerikilven välisissä kiinnitysruuveissa yllättävän suuriksi. Normaalin ruuvin murtoraja on 640 MPa:a, kun jännitys rungon ja laakerikilven välisissä kiinnitysruuveissa oli suurimmillaan 400 MPa:a. Rakenne oli kuitenkin varmalla puolella kestävyyden suhteen, koska keskimääräinen vetojännitys ruuveissa oli noin 200 MPa:a. Ruuvien jännityksiä voidaan pienentää lisäämällä kiinnitys-ruuvien lukumäärää tai kasvattamalla niiden kokoa. Koko moottorin kiinnitysruuveissa jännitys oli vain 4 MPa:a, koska osan kuormituksesta kantoi laakerikilven olakkeet.

Three-dimensional hydrodynamic numerical modelling of fold nappe formation, basement-cover deformation and slab detachment with applications to the helvetic nappe system (W Switzerland)

Many three-dimensional (3-D) structures in rock, which formed during the deformation of the Earth's crust and lithosphere, are controlled by a difference in mechanical strength between rock units and are often the result of a geometrical instability. Such structures are, for example, folds, pinch-and-swell structures (due to necking) or cuspate-lobate structures (mullions). These struc-tures occur from the centimeter to the kilometer scale and the related deformation processes con-trol the formation of, for example, fold-and-thrust belts and extensional sedimentary basins or the deformation of the basement-cover interface. The 2-D deformation processes causing these structures are relatively well studied, however, several processes during large-strain 3-D defor-mation are still incompletely understood. One of these 3-D processes is the lateral propagation of these structures, such as fold and cusp propagation in a direction orthogonal to the shortening direction or neck propagation in direction orthogonal to the extension direction. Especially, we are interested in fold nappes which are recumbent folds with amplitudes usually exceeding 10 km and they have been presumably formed by ductile shearing. They often exhibit a constant sense of shearing and a non-linear increase of shear strain towards their overturned limb. The fold axes of the Morcles fold nappe in western Switzerland plunges to the ENE whereas the fold axes in the more eastern Doldenhorn nappe plunges to the WSW. These opposite plunge direc-tions characterize the Rawil depression (Wildstrubel depression). The Morcles nappe is mainly the result of layer parallel contraction and shearing. During the compression the massive lime-stones were more competent than the surrounding marls and shales, which led to the buckling characteristics of the Morcles nappe, especially in the north-dipping normal limb. The Dolden-horn nappe exhibits only a minor overturned fold limb. There are still no 3-D numerical studies which investigate the fundamental dynamics of the formation of the large-scale 3-D structure including the Morcles and Doldenhorn nappes and the related Rawil depression. We study the 3-D evolution of geometrical instabilities and fold nappe formation with numerical simulations based on the finite element method (FEM). Simulating geometrical instabilities caused by sharp variations of mechanical strength between rock units requires a numerical algorithm that can accurately resolve material interfaces for large differences in material properties (e.g. between limestone and shale) and for large deformations. Therefore, our FE algorithm combines a nu-merical contour-line technique and a deformable Lagrangian mesh with re-meshing. With this combined method it is possible to accurately follow the initial material contours with the FE mesh and to accurately resolve the geometrical instabilities. The algorithm can simulate 3-D de-formation for a visco-elastic rheology. The viscous rheology is described by a power-law flow law. The code is used to study the 3-D fold nappe formation, the lateral propagation of folding and also the lateral propagation of cusps due to initial half graben geometry. Thereby, the small initial geometrical perturbations for folding and necking are exactly followed by the FE mesh, whereas the initial large perturbation describing a half graben is defined by a contour line inter-secting the finite elements. Further, the 3-D algorithm is applied to 3-D viscous nacking during slab detachment. The results from various simulations are compared with 2-D resulats and a 1-D analytical solution. -- On retrouve beaucoup de structures en 3 dimensions (3-D) dans les roches qui ont pour origines une déformation de la lithosphère terrestre. Ces structures sont par exemple des plis, des boudins (pinch-and-swell) ou des mullions (cuspate-lobate) et sont présentés de l'échelle centimétrique à kilométrique. Mécaniquement, ces structures peuvent être expliquées par une différence de résistance entre les différentes unités de roches et sont généralement le fruit d'une instabilité géométrique. Ces différences mécaniques entre les unités contrôlent non seulement les types de structures rencontrées, mais également le type de déformation (thick skin, thin skin) et le style tectonique (bassin d'avant pays, chaîne d'avant pays). Les processus de la déformation en deux dimensions (2-D) formant ces structures sont relativement bien compris. Cependant, lorsque l'on ajoute la troisiéme dimension, plusieurs processus ne sont pas complètement compris lors de la déformation à large échelle. L'un de ces processus est la propagation latérale des structures, par exemple la propagation de plis ou de mullions dans la direction perpendiculaire à l'axe de com-pression, ou la propagation des zones d'amincissement des boudins perpendiculairement à la direction d'extension. Nous sommes particulièrement intéressés les nappes de plis qui sont des nappes de charriage en forme de plis couché d'une amplitude plurikilométrique et étant formées par cisaillement ductile. La plupart du temps, elles exposent un sens de cisaillement constant et une augmentation non linéaire de la déformation vers la base du flanc inverse. Un exemple connu de nappes de plis est le domaine Helvétique dans les Alpes de l'ouest. Une de ces nap-pes est la Nappe de Morcles dont l'axe de pli plonge E-NE tandis que de l'autre côté de la dépression du Rawil (ou dépression du Wildstrubel), la nappe du Doldenhorn (équivalent de la nappe de Morcles) possède un axe de pli plongeant O-SO. La forme particulière de ces nappes est due à l'alternance de couches calcaires mécaniquement résistantes et de couches mécanique-ment faibles constituées de schistes et de marnes. Ces différences mécaniques dans les couches permettent d'expliquer les plissements internes à la nappe, particulièrement dans le flanc inver-se de la nappe de Morcles. Il faut également noter que le développement du flanc inverse des nappes n'est pas le même des deux côtés de la dépression de Rawil. Ainsi la nappe de Morcles possède un important flanc inverse alors que la nappe du Doldenhorn en est presque dépour-vue. A l'heure actuelle, aucune étude numérique en 3-D n'a été menée afin de comprendre la dynamique fondamentale de la formation des nappes de Morcles et du Doldenhorn ainsi que la formation de la dépression de Rawil. Ce travail propose la première analyse de l'évolution 3-D des instabilités géométriques et de la formation des nappes de plis en utilisant des simulations numériques. Notre modèle est basé sur la méthode des éléments finis (FEM) qui permet de ré-soudre avec précision les interfaces entre deux matériaux ayant des propriétés mécaniques très différentes (par exemple entre les couches calcaires et les couches marneuses). De plus nous utilisons un maillage lagrangien déformable avec une fonction de re-meshing (production d'un nouveau maillage). Grâce à cette méthode combinée il nous est possible de suivre avec précisi-on les interfaces matérielles et de résoudre avec précision les instabilités géométriques lors de la déformation de matériaux visco-élastiques décrit par une rhéologie non linéaire (n>1). Nous uti-lisons cet algorithme afin de comprendre la formation des nappes de plis, la propagation latérale du plissement ainsi que la propagation latérale des structures de type mullions causé par une va-riation latérale de la géométrie (p.ex graben). De plus l'algorithme est utilisé pour comprendre la dynamique 3-D de l'amincissement visqueux et de la rupture de la plaque descendante en zone de subduction. Les résultats obtenus sont comparés à des modèles 2-D et à la solution analytique 1-D. -- Viele drei dimensionale (3-D) Strukturen, die in Gesteinen vorkommen und durch die Verfor-mung der Erdkruste und Litosphäre entstanden sind werden von den unterschiedlichen mechani-schen Eigenschaften der Gesteinseinheiten kontrolliert und sind häufig das Resulat von geome-trischen Istabilitäten. Zu diesen strukturen zählen zum Beispiel Falten, Pich-and-swell Struktu-ren oder sogenannte Cusbate-Lobate Strukturen (auch Mullions). Diese Strukturen kommen in verschiedenen Grössenordungen vor und können Masse von einigen Zentimeter bis zu einigen Kilometer aufweisen. Die mit der Entstehung dieser Strukturen verbundenen Prozesse kontrol-lieren die Entstehung von Gerbirgen und Sediment-Becken sowie die Verformung des Kontaktes zwischen Grundgebirge und Stedimenten. Die zwei dimensionalen (2-D) Verformungs-Prozesse die zu den genannten Strukturen führen sind bereits sehr gut untersucht. Einige Prozesse wäh-rend starker 3-D Verformung sind hingegen noch unvollständig verstanden. Einer dieser 3-D Prozesse ist die seitliche Fortpflanzung der beschriebenen Strukturen, so wie die seitliche Fort-pflanzung von Falten und Cusbate-Lobate Strukturen senkrecht zur Verkürzungsrichtung und die seitliche Fortpflanzung von Pinch-and-Swell Strukturen othogonal zur Streckungsrichtung. Insbesondere interessieren wir uns für Faltendecken, liegende Falten mit Amplituden von mehr als 10 km. Faltendecken entstehen vermutlich durch duktile Verscherung. Sie zeigen oft einen konstanten Scherungssinn und eine nicht-lineare zunahme der Scherverformung am überkipp-ten Schenkel. Die Faltenachsen der Morcles Decke in der Westschweiz fallen Richtung ONO während die Faltenachsen der östicher gelegenen Doldenhorn Decke gegen WSW einfallen. Diese entgegengesetzten Einfallrichtungen charakterisieren die Rawil Depression (Wildstrubel Depression). Die Morcles Decke ist überwiegend das Resultat von Verkürzung und Scherung parallel zu den Sedimentlagen. Während der Verkürzung verhielt sich der massive Kalkstein kompetenter als der Umliegende Mergel und Schiefer, was zur Verfaltetung Morcles Decke führ-te, vorallem in gegen Norden eifallenden überkippten Schenkel. Die Doldenhorn Decke weist dagegen einen viel kleineren überkippten Schenkel und eine stärkere Lokalisierung der Verfor-mung auf. Bis heute gibt es keine 3-D numerischen Studien, die die fundamentale Dynamik der Entstehung von grossen stark verformten 3-D Strukturen wie den Morcles und Doldenhorn Decken sowie der damit verbudenen Rawil Depression untersuchen. Wir betrachten die 3-D Ent-wicklung von geometrischen Instabilitäten sowie die Entstehung fon Faltendecken mit Hilfe von numerischen Simulationen basiert auf der Finite Elemente Methode (FEM). Die Simulation von geometrischen Instabilitäten, die aufgrund von Änderungen der Materialeigenschaften zwischen verschiedenen Gesteinseinheiten entstehen, erfortert einen numerischen Algorithmus, der in der Lage ist die Materialgrenzen mit starkem Kontrast der Materialeigenschaften (zum Beispiel zwi-schen Kalksteineinheiten und Mergel) für starke Verfomung genau aufzulösen. Um dem gerecht zu werden kombiniert unser FE Algorithmus eine numerische Contour-Linien-Technik und ein deformierbares Lagranges Netz mit Re-meshing. Mit dieser kombinierten Methode ist es mög-lich den anfänglichen Materialgrenzen mit dem FE Netz genau zu folgen und die geometrischen Instabilitäten genügend aufzulösen. Der Algorithmus ist in der Lage visko-elastische 3-D Ver-formung zu rechnen, wobei die viskose Rheologie mit Hilfe eines power-law Fliessgesetzes beschrieben wird. Mit dem numerischen Algorithmus untersuchen wir die Entstehung von 3-D Faltendecken, die seitliche Fortpflanzung der Faltung sowie der Cusbate-Lobate Strukturen die sich durch die Verkürzung eines mit Sediment gefüllten Halbgraben bilden. Dabei werden die anfänglichen geometrischen Instabilitäten der Faltung exakt mit dem FE Netz aufgelöst wäh-rend die Materialgranzen des Halbgrabens die Finiten Elemente durchschneidet. Desweiteren wird der 3-D Algorithmus auf die Einschnürung während der 3-D viskosen Plattenablösung und Subduktion angewandt. Die 3-D Resultate werden mit 2-D Ergebnissen und einer 1-D analyti-schen Lösung verglichen.

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