Ziel - Die Zeit die ein Flugzeug benötigt, um auf eine bestimmte Höhe zu steigen (die Steigzeit) kann mit einer Formel berechnet werden, die vereinfachend annimmt, dass die Steiggeschwindigkeit über dem gesamten Steigflug mit zunehmender Höhe linear abnimmt. Ziel der Untersuchung ist, zu ermitteln, ob die Annahme einer linear abnehmenden Steiggeschwindigkeit realistisch ist bzw. welche Fehler sich aus der Annahme ergeben. ----- Methode - Mit der Höhe ändern sich Parameter wie Luftdichte, Widerstand, Schub und damit auch die optimale Fluggeschwindigkeit für den Steigflug. Die Parameter beeinflussen sich dabei gegenseitig. Der Schub wird dabei nach drei unterschiedlichen Methoden berechnet, gegeben von Bräunling, Scholz und Howe. Analysiert wird der Verlauf des Schubes mit der Höhe und der Verlauf der Steiggeschwindigkeit mit der Höhe für jede der drei Schubberechnungen. Abschließend wird für jede Schubberechnung die Steigzeit verglichen wie sie sich ergibt a) aus der einfachen Formel und b) aus einer Integrationsberechnung, bei der der Verlauf der Steiggeschwindigkeit durch eine Funktion beschrieben wird. ----- Ergebnisse - Die drei Schubberechnungen liefern ausgehend vom gleichen Startschub unterschiedliche Schübe in der Höhe. In die Methode nach Bräunling gehen mehr Parameter ein als in die anderen beiden Methoden. Es kann angenommen werden, dass die Methode nach Bräunling genauer ist, der Beweis kann aber nicht geführt werden. Der Schub nach Scholz und Howe fällt nahezu linear mit der Höhe ab. Der Schubverlauf nach Bräunling zeigt eine deutliche Nichtlinearität. Es wird die Steigzeit von 0 km auf 11 km Höhe berechnet nach a) und b), mit jeder der drei Schubberechnungen. Dabei wird jeweils der Unterschied in der Steigzeit ermittelt. Aufgrund der Nichtlinearität im Schubverlauf zeigt die Methode nach Bräunling dann auch den größten Unterschied zwischen den Berechnungsmethoden von 7,1 %. Bei einer Schubberechnung nach Scholz ergeben sich 1,7 % und nach Howe 1,4 %. Wenn bereits zu Beginn Vereinfachungen, z.B. bezüglich des Triebwerksschubes, vorgenommen wurden, ist es in Hinblick auf den Aufwand und die zu erreicheneden Ergebnisse möglich, und zum Teil sinnvoll, die Berechnungen der Steigzeit mittels linearer Abnahme der vertikalen Geschwindigkeit durchzuführen. Es wird ausdrücklich darauf hingewiesen, dass es hier um den Vergleich von zwei Methoden zur Berechnung der Steigzeit geht und nicht um die Bewertung von Methoden zur Schubberechnung (für die keine Vergleichswerte vorlagen). ----- Praktischer Nutzen - Es konnte festgestellt werden, dass eine einfache Formel zur Berechnung der Steigzeit mit geringem Fehler angewandt werden kann - insbesondere wenn Methoden zur Schubberechnung vorliegen, bei denen der Schub annähernd linear mit der Höhe abnimmt. Bei großem Aufwand und realitätsnaher Betrachtung, z.B. nach Bräunling, führt der lineare Ansatz jedoch zu einem zu großen Fehler. Hierfür sollte die Berechnung der Steigzeit mittels Integration durchgeführt werden.

Articulated Funiculator is a new and innovative concept developed by Tyréns forachieving a more efficient vertical transportation with a higher space utilization.Having a variety of merits, i.e.: simple construction, direct electromagneticthrust propulsion, and high safety and reliability in contrast to rotary inductionmotor, linear induction motor (LIM) is considered to be one of the cases as thepropulsion system for Articulated Funiculator. The thesis is then carried outwith the purpose of determining the feasibility of this study case by designing theLIMs meeting some specific requirements. The detailed requirements include: aset of identical LIMs are required to jointly produce the thrust that is sufficientto vertically raise the moving system up to 2 m/s2; the size of the LIMs cannotexceed the specification of the funiculator; the maximum flux density in the airgap for each LIM is kept slightly below 0.6 T; no iron saturation of any part ofthe LIMs is allowed.In this thesis report, an introduction of LIM is firstly presented. Followingthe introduction, relevant literature has been reviewed for a strengthenedtheoretical fundamentals and a better understanding of LIM’s history and applications. A general classification of LIMs is subsequently introduced. In addtion,an analytical model of the single-sided linear induction motor (SLIM) has beenbuilt based on an approximate equivalent circuit, and the preliminary geometryof the SLIM is thereby obtained. In order to acquire a more comprehensiveunderstanding of the machine characteristics and a more precise SLIM design, atwo-dimensional finite element method (2D-FEM) analysis is performed initiallyaccording to the preliminary geometry. The results, unfortunately, turn out tobe iron severely saturated in the teeth and yoke, and a excessive maximumvalue of air-gap flux density. Specific to the problems, different parameters ofthe SLIM are marginally adjusted and a series of design scenarios are run inFlux2D for 8-pole and 6-pole SLIM. The comparisons between the results areconducted and the final solution is lastly chosen among them. / Articulated Funiculator är ett nytt och innovativt koncept som utvecklats av Tyréns för att möjilggöra en mer effektiv vertikal transport och bättre utnyttjautrymme. Tack vare fördelar såsom en enkel konstruktion, direkt elektromagnetiskdragkraftsframdrivning, samt hög säkerhet och tillförlitlighet i motsatstill roterande induktionsmotor, är en linjär induktionsmotor (LIM) aktuell somframdrivningssystem. Detta examensarbete är utfört med syfte att utforma enLIM för att uppfylla vissa specifika krav. De detaljerade kraven inkluderar: enuppsättning identiska LIM krävs för att gemensamt producera tillräcklig dragkraftför att vertikalt höja det rörliga systemet upp till 2 m/s2; storleken påLIM får inte överstiga specifikation; den maximala flödestätheten i luftgapet förvarje LIM hålls är begränsad till knappt 0.6 T; ingen järnmättnad av någon delav LIM är tillåtet. I denna rapport ges först en introduktion av LIM-konceptet. Efter introduktionenhar relevant litteratur granskats för att stärka teoretiska grundkunskapersamt ge en bättre belysning av historiken kring LIMs samt dess applikationer. Utöver detta har en analytisk modell av den ensidiga linjära induktionsmotorn(SLIM) byggts, baserat på en ungefärlig ekvivalent krets med vilket den preliminärageometrin för SLIM. För att erhålla en mer grundläggande förståelse avmaskinens egenskaper är en tvådimensionell analys med finita elementmetoden(2D-FEM) utförd, initialt med användande av en preliminär geometri erhållenmed hjälp av analytisk dimensionering. Resultaten från dessa simuleringar visadedock att järnet mättats kraftigt i både tänderna och oket och ett överdrivetstort maximivärde av luftgapets flödestäthet erhålls. Specifikt för applikationenjusteras olika parametrar och en rad driftscenarier körs i Flux2D för en 8-poligoch en 6-polig SLIM. En slutgiltig jämförelse mellan de olika maskindesignernapresenteras och den rekommenderade lösningen väljs slutligen.

No description available.

The Simpson Mountains have long been of economic interest and have renewed interest in their potential value. Field mapping of the project area redefined structural relationships between stratigraphic units. Geometric and kinematic analysis of structures in the Simpson Mountains show the range is deformed by the three most recent tectonic events: the Sevier Orogeny, the Laramide Orogeny, and Basin and Range Extension. Laramide structures define the range with a significant E-W normal fault and an E-W thrust fault, which are both likely related to Eocene-age igneous intrusions. Principal component analysis (PCA) of regional quartzite X-ray Fluorescence (XRF) data resulted in distinctive populations between the Eureka Quartzite and the Mutual and Prospect Mountain Quartzites. The PCA was paired with petrographic analysis of regional quartzites where samples were diagnostically classified to help validate the PCA results. XRF analysis of volcanic rocks show volcanic arc origin. 40Ar/39Ar dating of the volcanic rocks associated with the intrusions yield new ages of 34.09±0.10 to 37.05±0.06 Ma and 19.11±0.02 to 19.18±0.03. Lithostratigraphy of the map area was validated by identification of fossil samples. The Eocene intrusions are likely sources of mineralization in the range along older Sevier structures.

駆動プーリ上の回転変動が金属Vベルトを介して従動プーリへと伝達される際には，摩擦力が飽和状態に近づくにつれ，従動プーリへ伝達される回転変動は減衰する．この回転変動の変化に着目して滑り状態を指標化した． / When fluctuations in the speed of rotation of the drive pulley are transmitted to the driven pulley via the metal V-belt, the transmitted fluctuations become attenuated as friction force approaches a state of saturation. The research discussed in this paper focused on these fluctuations in the speed of rotation and developed an index for the slip state between the belt and the pulleys. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

Chapter 1-2:The Cassini RADAR mapper has imaged elevated blocks and mountains on Titan we term ‘ridges’. Two unresolved problems regarding Titan's surface are still debated: what is the origin of its ridges and was there tectonic activity on Titan? To understand the processes that produced the ridges, in this study, (1) we analyze the distribution and orientation of ridges through systematic geomorphologic mapping and (2) we compare the location of the ridges to a new global topographic map to explore the correlation between elevation and ridges and the implications for Titan's surface evolution. Globally, the orientation of ridges is nearly E-W and the ridges are more common near the equator than at the poles, which suggests a tectonic origin for most of the ridges on Titan. In addition, the ridges are found to preferentially lie at higher-than-average elevations near the equator. We conclude the most reasonable formation scenario for Titan's ridges is that contractional tectonism built the ridges and thickened the icy lithosphere, causing regional uplift. The combination of global and regional tectonic events, likely contractional in nature, plus enhanced fluvial erosion and sedimentation near the poles, would have contributed to shaping Titan's tectonic landforms and surface morphology to what we see today. However, contractional structures (i.e. thrusts and folds) require large stresses (8~10 MPa), the sources of which probably do not exist on Titan. Liquid hydrocarbons in Titan's near subsurface must play a role similar to that of water on Earth and lead to fluid overpressures, which enable contractional deformation at smaller stresses (< 1MPa) by significantly reducing the shear strength of materials. We show that crustal conditions with enhanced pore fluid pressures on Titan favor the formation of thrust faults and related folds, in a contractional stress field. The production of folds, as on Earth, is facilitated by the presence of crustal liquids to weaken the crust. These hydrocarbon fluids have played a key role in Titan's tectonic evolutionary history, leaving it the only icy body on which strong evidence for contractional tectonism exists. Chapter 3: Arthur Wichmann's ‘Earthquakes of the Indian Archipelago’ documents several large earthquakes and tsunami throughout the Banda Arc region that can be interpreted as mega-thrust events. However, the source regions of these events are not known. One of the largest and well-documented events in the catalog is the great earthquake and tsunami affecting the Banda islands on 1 August 1629. It caused severe damage from a 15-meter tsunami that arrived at the Banda Islands about a half hour after violent shaking stopped. The earthquake was also recorded 230 km away in Ambon, but no tsunami is mentioned. This event was followed by at least 9 years of uncommonly frequent seismic activity in the region that tapered off with time, which can be interpreted as aftershocks. The combination of these observations indicates that the earthquake was most likely a mega-thrust event. We use an inverse modeling approach to numerically reconstruct the tsunami, which constrains the likely location and magnitude of the 1629 earthquake. Only linear numerical models are applied due to the low-resolution of bathymetry in the Banda Islands and Ambon. Therefore, we apply various wave amplification factors (1.5 to 4) derived from simulations of recent, well-constrained tsunami to bracket the upper and lower limits of earthquake moment magnitudes for the event. The closest major earthquake sources to the Banda Islands are the Tanimbar and Seram Troughs of the Banda subduction/collision zone. Other source regions are too far away for such a short arrival time of the tsunami after shaking. Moment magnitudes predicted by the models in order to produce a 15 m tsunami are Mw of 9.8 to 9.2 on the Tanimbar Trough and Mw 8.8 to 8.2 on the Seram Trough. The arrival times of these waves are 58 minutes for Tanimbar Trough and 30 minutes for Seram Trough. The model also predicts 5 meters run-up for Ambon from a Tanimbar Trough source, which is inconsistent with the historical records. Ambon is mostly shielded from a wave generated by a Seram Trough Source.We conclude that the most likely source of the 1629 mega-thrust earthquake is the Seram Trough. Only one earthquake > Mw 8.0 is recorded instrumentally from the eastern Indonesia region although high rates of strain (50-80 mm/a) are measured across the Seram section of the Banda subduction zone. Enough strain has already accumulated since the last major historical event to produce an earthquake of similar size to the 1629 event. Due to the rapid population growth in coastal areas in this region, it is imperative that the most vulnerable coastal areas prepare accordingly.

<p dir="ltr"> With NASA's Artemis program and international collaborations focused on building a sustainable infrastructure for human exploration of the Moon, there is a growing demand for lunar exploration and complex spaceflight operations in cislunar space. However, designing efficient transfer trajectories between the Earth and the Moon remains complex and challenging. This investigation focuses on developing a dynamically informed framework for constructing low-energy transfers in the Earth-Moon-Sun Bicircular Restricted Four-body Problem (BCR4BP). Techniques within dynamical systems theory and numerical methods are exploited to construct transfers to various cislunar orbits. The analysis aims to contribute to a deeper understanding of the dynamical structures governing spacecraft motion. It addresses the characteristics of dynamical structures that facilitate the construction of propellant-efficient pathways between the Earth and the Moon, exploring periodic structures and energy properties from the Circular Restricted Three-body Problem (CR3BP) and BCR4BP. The investigation also focuses on constructing families of low-energy transfers by incorporating electric propulsion, i.e., low thrust, in an effort to reduce the time of flight and offer alternative transfer geometries. Additionally, the investigation introduces a process to transition solutions to the higher fidelity ephemeris force model to accurately model spacecraft motion through the Earth-Moon-Sun system. This research provides insights into constructing families of ballistic lunar transfers (BLTs) and cislunar low-energy flight paths (CLEFs), offering a foundation for future mission design and exploration of the Earth-Moon system.</p>

<p dir="ltr">Rolling element bearings (REBs) are common components in rotating equipment. They are used to carry loads and allow for rotation and misalignments with minimal friction. There exists a wide variety of ball and roller bearings that are suited for a wide variety of applications. All varieties of REBs operate with the same fundamental principles: force transferred from the shaft is applied to the inner race of a bearing, distributed among the rolling elements, and passed on through the outer race to the bearing housing. Load distribution among the rolling elements and the dynamic performance of the bearing is dependent on the bearing’s specifications and operating conditions. Bearing-housing and inner race-shaft fit classifications also control the bearing radial internal clearance (RIC), which eventually affects the bearing performance and load transferred to the housing.</p><p dir="ltr">This thesis experimentally and analytically investigates the load distribution and dynamic performance of rolling elements and investigates roller slip, tilt, and skew in a spherical roller bearing (SRB) under various combinations of loads and speeds. In order to have better insight into the effect of flexible housing and shaft on load distribution and dynamics of REBs, it was experimentally investigated the variation of inner race-shaft and outer race-housing interfaces on load and pressure maps at the bearing-housing interface for four different varieties of rolling element bearing: deep groove ball bearings, angular contact ball bearings, cylindrical roller bearings, and spherical roller bearings. Moreover, an integrated rotor-bearing housing system model developed to examine the behaviors of the rotor, bearing, and housing operating under various conditions.</p><p dir="ltr">In order to gain a deeper understanding of the dynamic behavior of REBs, a full six degree of freedom SRB dynamic model was developed in MSC ADAMS software. C++ based ADAMS/Solver subroutines, called dynamic bearing model (DBM), were developed and incorporated in ADAMS to compute reaction forces and moments in a rolling element bearing. DBM is based on the discrete element method (DEM), which assumes each of the bearing elements (i.e., rolling elements, cage, inner race, and outer race) to be a rigid body with six degrees-of freedom (DOF) in a three-dimensional space. A novel test rig (spherical roller bearing test rig, SRBTR) was also designed and developed to investigate load distribution and roller slip, tilt, and skew in an SRB. The test rig utilized a double-row SRB and was designed to allow for direct visual access to each row using a high-speed camera. The dynamic behavior of the rollers was corroborated with the developed analytical model. The experimental and analytical results indicate that the roller tilt angle increases with axial load, remains constant with speed, and decreases with increasing radial load when the roller is located in the load zone. Furthermore, roller skew in the load zone increases with axial load and shaft speed; however, it decreases with the radial load. The results indicate that when the radial-to-axial load ratio is greater than 4, roller tilt and skew are minimized. Due to roller intermittent slip and roller cage pocket collision in the unload zone, tilt and skew become unpredictable. The magnitude of the tilt and skew in the unload zone is directly related to the roller-race and roller-cage pocket clearances, respectively. Another test rig (pressure mapping test rig, PMTR) was designed to solely investigate how bearing-housing and inner race-shaft interfaces affect the load distribution in REBs. Thin film pressure sensors were utilized and placed around the perimeter of the test bearings inside of a housing to experimentally evaluate the pressure distribution between REBs and a housing under different loads and bearing-shaft and bearing-housing interfaces. Pressure map results were used to evaluate the effect of radial internal clearance on the load distribution of different bearing types. Pressure map results confirmed that the amplitude of load variation reduces with the bearing internal clearance. The thin film sensor system was also used to investigate the circumferential load distribution on the housing.</p><p dir="ltr">Previous ADAMS bearing models have assumed the bearing outer race to be fixed to the ground and the bearing inner race to be attached to a rigid shaft. In order to develop a more realistic and versatile bearing simulation tool, ADAMS bearing models were combined with flexible housings and rotor. To achieve an integrated rotor-bearing housing system model, the ADAMS bearing model was coupled through a set of interface points using component-mode-synthesis (CMS) for the rotor and housing model. The bearing outer races were discretized into multiple nodes to compute the force and deformation at the bearing housing conformal contact as well as to minimize the computational requirements associated with the conformal contact problems. The integrated model was then utilized to investigate the effects of rotor flexibility in the bearing rotor system and the effect of bearing clearance and housing clearance on bearing dynamics. It was demonstrated that the flexibility of the rotor has a significant effect on bearing element motion and dynamics. The results also indicated that depending on the bearing type, the shaft deflection can induce a moment within the bearing that is not readily identifiable from elementary theory. The results showed that the flexible housing undergoes deformations that create ovality in the bearing housing, thus affecting bearing dynamics. The model was also used to investigate bearing performance in a miniature wind turbine main shaft, utilizing a combination of SRB and cylindrical roller bearing (CRB) ADAMS models. Results suggest that the axial-to-radial load ratio should be less than the tangent of the SRB contact angle to avoid premature failure due to rollers sliding in the SRB as well as detrimental parallel misalignment in the CRB.</p>

MRO-industrin är en kritisk del för underhåll inom flygindustrin och arbetsprocesserna ser olika ut från företag till företag. För att kunna utföra ett så säkert och kvalitetsmässigt arbete som möjligt så är det viktigt att riskbedöma samt minimera existerande risker i operationen för att säkerställa kvalitet till kund samt säkerhet för arbetare. Uppdragsgivaren ST Engineering Aerospace Solutions (STEAS) är det ledande företaget i Sverige när det gäller MRO arbete och med den ständiga utvecklingen av utrustning upptäcks det allt fler risker som kräver analyser och minimering. Forskning har tidigare gjorts på hur fixtur design kan förbättras ergonomiskt m h a virtuell miljöteknik. Detta för att kunna minimera design och tillverkningskostnader med hänsyn till itereringsprocessen. Detta i kombination med studier gjorda på muskuloskeletala skador med kopplingar till MRO-industrin belyser behovet av riskanalys i MRO industrin. Arbetet hos STEAS går ut på att utföra riskanalyser ur ett tekniskt, ergonomiskt och ekonomiskt perspektiv på deras rörliga fixturer samt kemiska processer som behandlar diverse komponenter av motornacellet. Detta för att STEAS sedan ska kunna kolla på eventuella kostnader och implementera de rekommenderade åtgärderna. Analysmetoderna som används är en PHL (Preliminary Hazard List), FMEA (Failure Modes and Effects Analysis) och en ACHB analys (Accidental Cost &amp; Hypothetical Benefit) / The MRO industry is a critical part of maintenance in the aviation industry where the work processes differ from company to company. In order to be able to perform as safe and high-quality work as possible, it is important to assess risks and minimize existing risks in the operation to ensure quality for customers and safety for workers. The client ST Engineering Aerospace Solutions (STEAS) is the leading company in Sweden interms of MRO work and with the constant development of equipment, more and more risks are discovered that require analysis and minimization. Research has previously been done on how fixture design can be improved ergonomically using virtual environment technology. This is to be able to minimize design and manufacturing costs with regard to the iteration process. This in combination with studies done on musculoskeletal injuries with connections to the MRO industry highlights the need for risk analysis in the MRO industry. The work at STEAS consists of performing risk analysis from a technical, ergonomic and financial perspective on their moving fixtures and chemical processes so that STEAS can then check for possible costs and implement the recommended measures. The analysis methods used are a PHL (Preliminary Hazard List), FMEA (Failure Modes and Effects Analysis) and an ACHB analysis (Accidental Cost &amp; Hypothetical Benefit)

Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.