Dissertations / Theses: 'Design stresses'

1

Parvizian, Jamshid. "Shape design optimization using boundary elements." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267165.

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2

Bond, Andrew John. "Behaviour of displacement piles in overconsolidated clays." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/7781.

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3

Quan, Yuyun 1973. "Finite element analysis of tumbling mill design and operating effects on liner bolt stresses, liner stresses and mill resonance." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99012.

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Tumbling mills describe a class of mechanical systems defined by a cylindrical chamber filled with balls and/or rocks that rotate around their own longitudinal axis. Due to the action of charges, the lifters/liners wear significantly and their shape will be changed which will influence the efficiency of the mill. Liner bolts are the mill components which connect the mill interior with the exterior environment. With this property, bolts have been paid more and more attention. The first part of the thesis covers the structural analysis of the lifter/liner bolts, and the possibility for on-line charge motion measurement with the aid of bolts is discussed by comparing the strain distributions at the bolt areas where the bolts occupy different mill circumferential positions. In order to measure the lifter/liner wear, a real-time, on-line wear sensor was developed by the Comminution Dynamics Laboratory. However, the positioning of the sensor/sensors affects the strength of the mill is unknown. The second part of the project provides detailed research on this issue by FEA analysis so as to provide a basis for the practical application of this kind of sensors. Finally, during the grinding process of tumbling mills, some mills can vibrate greatly at some ranges of mill rotating speeds and as a result the mills cannot work properly because of this vibration or resonance. With six different mill models, the final part of the thesis investigates the mill natural frequencies and their modes by FEA and furthermore, explores the effect of mill diameter, length on these frequencies and modes.

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Hanna, Carl Robert. "Engineering Residual Stress into the Workpiece through the Design of Machining Process Parameters." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19813.

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The surface integrity of a machined component that meets the demands of a specific application requirement is defined by several characteristics. The residual stress profile into the component is often considered as the critical characteristics as it carries a direct effect on the fatigue life of a machined component. A significant amount of effort has been dedicated by researchers to predict post process stress in a workpiece using analytical, experimental, and numerical modeling methods. Nonetheless, no methodology is available that can express the cutting process parameters and tool geometry parameters as functions of machined residual stress profile to allow process planning in achieving desired residual stress profile. This research seeks to fill that void by developing a novel approach to enable the extraction of cutting process and tool geometry parameters from a desired or required residual stress profile. More specifically, the model consists in determining the depth of cut, the tool edge radius and the cutting forces needed to obtain a prescribed residual stress profile for an orthogonal machining operation. The model is based on the inverse solution of a physics-based modeling approach of the orthogonal machining operation and the inverse solution of the residual stress prediction from Hertzian stresses. Experimental and modeling data are used to validate the developed model. The work constitutes a novel approach in engineering residual stress in a machined component.

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JEFFREY, ROBERT GRAHAM JR. "ROCKBOLT ANALYSIS FOR REINFORCEMENT AND DESIGN IN LAYERED ROCK (COMPOSITE)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187982.

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The displacements and stresses in layered rock above underground openings can be calculated using a beam model for the rock layers. The traditional approach assumes that interfaces between layers are frictionless and layers can slip past one another freely as they deflect. In contrast, the design of structural laminated beams has traditionally been based on the assumption that the interfaces between layers were welded, with no slip occurring there. In this work, the theory of composite laminated beams, which allows for partial slip on layer interfaces, is applied to the problem of predicting displacements and stresses in layered roof rock. The effects of rockbolt reinforcement are modeled by discrete shear and normal stiffnesses incorporated at locations in the model where the rockbolts cross layer interfaces. Published solutions and results for laminated composite beams are reviewed. Composite laminated beam theory provided a means of accounting for rockbolt reinforcement effects and provided a conceptual framework that was used to develop two FORTRAN programs; one, based on the force method of analysis, that automatically finds shear and tensile interface failures in the system, and the other a finite element program that employs beam elements, elastic interface elements, and rockbolt elements to model a rockbolted layered rock system. Published data together with results from these programs suggest that shear reinforcement may be more effective when placed near the ends of roof layers. The normal interaction between layers tends to be uniformly distributed unless rockbolt forces act on the layers or if partial delamination of layers has occurred. Both shear and normal reinforcement will cause stresses to be redistributed within the system of layers. Analysis of this redistribution of stresses requires that the sequence of interface failure be predicted which, in turn, requires that the properties of the individual layers, of the interfaces between layers, and of the rockbolts be properly taken into account. Laminated composite beam theory and programs based on this theory provide rational and efficient ways to study and analyze the behavior of layered roof rock.

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6

Wamelen, Arend Andries van. "Optimal design and testing of laminated specimens to evaluate competing composite failure criteria." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08042009-040517/.

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7

Willis, C. R. "Design of unreinforced masonry walls for out-of-plane loading /." Title page, abstract and table of contents only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phw7342.pdf.

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8

Malm, Richard. "Shear cracks in concrete structures subjected to in-plane stresses." Licentiate thesis, KTH, Civil and Architectural Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4215.

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After only two years of service, extensive cracking was found in the webs of two light-rail commuter line bridges in Stockholm, the Gröndal and Alvik bridges. Due to this incident it was found necessary to study the means available for analysing shear cracking in concrete structures subjected to in-plane stresses. The aim of this PhD project is to study shear cracking with these two bridges as reference. In this thesis, the first part aims to study the possibility of using finite element analysis as a tool for predicting shear cracking for plane state stresses. The second part is concerning how the shear cracks are treated in the concrete design standards.

Shear cracking in reinforced beams has been studied with non-linear finite element analyses. In these analyses the shear cracking behaviour was compared to experiments conducted to analyse the shear failure behaviour. Finite element analyses were performed with two different FE programs Abaqus and Atena. The material model used in Atena is a smeared crack model based on damage and fracture theory with either fixed or rotated crack direction. The material model used in Abaqus is based on plasticity and damage theory. The fixed crack model in Atena and the model in Abaqus gave good results for all studied beams. For the two studied deep beams with flanges the results from the rotated crack model were almost the same as obtained with the fixed crack model. The rotated crack model in Atena gave though for some beams a rather poor estimation of the behaviour.

The calculation of crack widths of shear cracks has been studied for the long-term load case in the serviceability state for the Gröndal and Alvik bridges, with the means available in the design standards. The methods based on the crack direction corresponding to the principal stress and do not include the effect of aggregate interlocking seems to be too conservative. Two of the studied methods included the effect of aggregate interlocking, it was made either by introducing stresses in the crack plane or implicitly by changing the direction of the crack so that it no longer coincide with the direction of principal stress. For calculations based on probable load conditions, these methods gave estimations of the crack widths that were close to the ones observed at the bridges. Continuous measurements of cracks at the Gröndal and the Alvik bridges have also been included. Monitoring revealed that the strengthening work with post-tensioned tendons has, so far, been successful. It also revealed that the crack width variations after strengthening are mainly temperature dependent where the daily temperature variation creates movements ten times greater than those from a passing light-rail vehicle. Monitoring a crack between the top flange and the webs on the Gröndal Bridge showed that the top flange was moving in a longitudinal direction relative to the web until the strengthening was completed. The crack widths in the sections strengthened solely by carbon fibre laminates seem to increase due to long-term effects.

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9

Peter, Geoffrey J. M. "Numerical simulation of CTE mismatch and thermal-structural stresses in the design of interconnects /." Full text open access at:, 2001. http://content.ohsu.edu/u?/etd,235.

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10

Graesser, Douglas Lee. "Design of laminated composite panels optimized for damage tolerance /." Thesis, Connect to this title online; UW restricted, 1993. http://hdl.handle.net/1773/7080.

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11

Kulkarni, Vinod Dilip. "Integration of micromachined thermal shear stress sensors with microchannels : design, fabrication and testing /." Online version of thesis, 2005. http://hdl.handle.net/1850/5201.

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12

Shoukr, Shoukry Latif. "Contact stresses in interference-fit joints with application to sugar-mill roller assemblies." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184928.

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The interference-fit joint is widely used in machine design to connect two cylindrical machine elements. Its popularity comes from the simplicity of the assembly and the low cost of the production process. Even so, no study has examined the boundary non-linearities in the assembly of these joints. Moreover, the contact stresses and the stress concentration factors in interference-fit joints under torsional loads have not yet been examined in detail. In addition, the interface stresses and stress concentration factors in interference-fit joints subjected to bending loads have not been approached theoretically before. The sugar-mill roller is one of the oldest and most important examples of the interference-fit joints. The frequent fatigue failure of the sugar-mill rollers under reversed bending causes costly emergency line-shut downs. The versatility of the finite element method and the capability of the point-matching technique in handling contact problems have been combined, in the present work, to produce a surface-matching technique. It has been found that the complete-cohesion contact assumption may be acceptable for coefficients of friction ≥ 0.2, which is the case for most of the normally machined surfaces. An approach combining the semi-inverse displacement finite element method and the surface-matching technique has been developed to perform the torsional analysis. It has been found that the governing non-dimensional quantities are the ratio of the cohesion-length to the interface-length and the coefficient of friction divided by the load-level. The load-level is the ratio between the angle of twist of the shaft per unit length when the torque acts on the shaft alone and the amount of the diametral interference divided by the shaft diameter. A finite element model, using 8-noded solid elements together with linear interface elements, has been employed to locate the cohesion and slippage-zones in the sugar-mill roller under bending. The contact pressure increases along the compression side and decreases along the tension side. On the contrary, the interface shear decreases along the compression side due to bending and increases along the tension side. Subsequently, a larger slippage-length has been detected along the tension side.

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13

Peng, Jun, and 彭军. "Strain gradient effects on flexural strength and ductility design of normal-strength RC beams and columns." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48329630.

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The stress-strain characteristics of concrete developed in flexure is very important for flexural strength design of reinforced concrete (RC) members. In current RC design codes, the stress-strain curve of concrete developed in flexure is obtained by scaling down the uni-axial stress-strain curve to account for the strain gradient effect. Therefore, the maximum concrete stress that can be developed under flexure is smaller than its uni-axial strength, and the use of which always underestimates the flexural strength of RC beams and columns even though the safety factors for materials are taken as unity. Furthermore, the value of strength underestimation was different for RC beams and columns, which indicates that the extent of strain gradient will affect the maximum concrete stress and stress-strain curve developed under flexure. To investigate the maximum concrete stress, 29 column specimens were fabricated and tested in this study. They were divided into 9 groups, each of which was poured from the same batch of concrete and contained specimens with identical cross-section properties. In each group, one specimen was tested under concentric load while the rest was/were subjected to eccentric or horizontal load. To study the strain gradient effects, the ratio of the maximum concrete compressive stress developed in the eccentrically/horizontally loaded specimens to the maximum uni-axial compressive stress developed in the counterpart concentrically loaded specimens, denoted by k3, is determined based on axial force and moment equilibriums. Subsequently, the concrete stress block parameters and the equivalent rectangular concrete stress block parameters are determined. It is found that the ratios of the maximum and equivalent concrete stress to uni-axial cylinder strength, denoted respectively by k3 and , depend significantly on strain gradient, while that of the depth of stress block to neutral axis depth, denoted by , remains relatively constant with strain gradient. Design equations are proposed to relate and  with strain gradient for strength calculation, whose applicability is verified by comparing the strengths of RC beams and columns tested by various researchers with their theoretical strengths predicted by the proposed parameters and those evaluated based on provisions of RC codes. Based on the test results, the stress-strain curve of normal-strength concrete (NSC) developed under strain gradient is derived using least-square method by minimising the errors between the theoretical axial load and moment and the respective measured values. Two formulas are developed to derive the flexural stress-strain curve, whose applicability is verified by comparing the predicted strength with those measured by other researchers. Lastly, the application of the proposed stress-block parameters and stress-strain curve of NSC will be illustrated by developing some charts for flexural strength design of NSC beams and columns. The application will further be extended to develop strength-ductility charts for NSC beams and columns, which enable simultaneous design of strength and ductility. By adopting the proposed design charts, the flexural strength design, as well as that of the plastic hinge forming mechanism during extreme events, will be more accurate. The resulting design will be safer, more environmentally friendly and cost effective.
published_or_final_version
Civil Engineering
Doctoral
Doctor of Philosophy

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14

Li, Felicia. "Study of Gear design Concept to Reduce Root Bending- & Contact Stresses for Automotive Transmission." Thesis, Karlstads universitet, Institutionen för ingenjörsvetenskap och fysik (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-74532.

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Advanced technologies for the automotive industry require improved designed precision in diﬀerent areas. Research is needed in order to meet customer demand and satisfaction to increase durability, eﬃciency, and reliability. That is why continuous development in transmission system has been an exciting topic for many years. The gears in the transmission system demand high resistance against repeated loads acting on the teeth and the ability to engage without energy loss. The intention is to support that eﬀort by investigating seven design cases of a parallel helical gear pair. This master thesis aims to study a gear design concept of adding a supporting ring to reduce the root bending- and contact stresses. To implement this study, seven diﬀerent design cases were modelled to study the eﬀect of changing the design. One or two support ring structures were added, or the thickness was increased of the gear considered exposed to high stresses. The purpose is to gain a comparative advantage in the automotive industry. M1 is a reference standard design, while the other models (M2-M5/P1-P3) are modiﬁed designs with additional rings or changed in thickness. Simulation is an eﬀective and an useful tool to understand and visualize how the complex interaction of the transmission component appears to be. A ﬁnite element method (FEM) program was used to investigate these models. The gear pairs were imported into the pre-processor ANSA, the FEM program Abaqus 2017 was used as a solver, and the results were extracted from the post-processor META. To support the aim of this thesis, two of the seven FEM models were validated against a specialized gear calculated program, WindowsLDP, in order to determine the robustness of the simulation models. The transmission error (TE) measurements, root bending- and contact stresses were observed for the validation. Introducing the diﬀerent models M3-M5 and P1-P3, the root and contact stresses were reduced by 1.2-4.4 and 0.07-4.3 %, respectively, compared to M1. The transmission error TE could diﬀer as much as 85% in M2-M3 as compared to M1. Systematic errors were generated in model M2, therefore the low root stresses obtained in M2 should be considered carefully. Implementing the so-called misalignment measurement, tilting parameter, microgeometry, and proﬁle modiﬁcation related to crowning and tip relief is discussed and believed to reduce TE measurements, root- and contact stresses. These modiﬁcations have not been studied in this thesis. The LDP results showed a trend of higher values compared to the FEM results, which was suggested to be further investigated in the future.
Dagens avancerade teknik inom fordonsindustrin kräver förbättrad precision hos konstruktioner inom olika områden. Forskning behövs för att möta kundernas efterfrågan och för att öka hållbarhet, eﬀektivitet och tillförlitlighet. Detta är varför kontinuerlig utvecklingen av växellådssystem har varit ett hett ämne i många år. Kugghjulstransmission skall ha högt motstånd mot upprepande belastning som förekommer på tänderna och skall även ha en minimal energiförlust. Detta examensarbete siktar mot att stödja den fortsatta utvecklingen inom området genom en fallstudie, mer speciﬁkt för att studera sju olika kugghjulsmodeller som behandlar ett parallellt spiralformade kugghjul. Målet med detta examensarbete är att studera ett kugghjulskoncept där en ring appliceras för att reducera rot- och kontaktspänningar. Utförandet sker genom att studera sju olika modeller, för att veta hur stor påverkan designen utgör. En eller två stödringstrukturer appliceras, eller att öka kuggbredden på det kugghjul som anses vara det mest kritiska för höga spänningar. Denna studie görs för att kugghjulstillverkaren ska vara i utvecklingens framkant och kunna konkurrera inom fordonsindustrin. M1 ären referens och standard designmodell, medan de andra modellerna (M2-M5/ P1-P3) är modiﬁerade design där med ytterligare ringar eller ändrad kuggbredd. Simulering är en eﬀektiv metod för att förstå och visualisera komplexiteten av komponenter inom växellådan. Ett ﬁnita elementmetodens program användes för att undersöka dessa modeller, genom att importera geometrierna till pre-processorn ANSA, där Abaqus 2017 användes som en lösare, där sedan resultaten extraheras från post-processorn META. För att stödja denna studien användes två av de sju FEM-modellerna till att valideras mot ett annat specialiserat kugghjulsprogram inom kuggberäkning som heter WindowsLDP. Detta med avsikt att fastställa simuleringsmodellernas robusthet. Det så kallade överföringsfelet, rotböjnings- och kontaktspänningarna var ingående parametrar som behandlades under valideringen. Modellerna M3-M5/P1-P3 introducerades, där rotböjsspänningen och kontaktspänningen reducerades med 1.2-4.4 och 0.07-4.3% när de jämfördes med M1. Överföringsfelet (TE) kunde skilja upp mot 85% mellan M2-M3 jämfört med M1. Ett systematiskt fel uppstod i modell M2, modellens robusthet kunde därmed ej fastställas, då modellens resultat bör övervägas noggrant. Införande av så kallade växelförskjutning, lutning/vippning parametrar, mikrogeometrier och proﬁlmodiﬁeringen relaterat till kronning och tipavlastning, kommer att genera minskade TE-mätningar samt rot- och kontaktspänningar för de spiralformade kugghjulen. Dessa ämne har ej studerats under detta examensarbete. LDP-resultaten visade högre värden relativt jämfört med de FEM resultat, där en trend kunde observeras. Slutsatsen föreslog att detta bör undersökas ytterligare i framtiden.

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15

Jobe, Jeffrey M. "Blast resistant forced entrty [sic] steel stud wall design." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/5850.

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Thesis (M.S.)--University of Missouri-Columbia, 2005.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 23, 2007) Includes bibliographical references.

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16

Zhong, Hai. "Dynamic Interaction of Vehicle and Bridge Subjected to Prestress Force Loss and Foundation Settlement." Diss., North Dakota State University, 2016. http://hdl.handle.net/10365/25662.

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Plenty of bridges in U.S. are suffering from prestress force loss and foundation settlements. The loss of prestress force in bridge load-carrying members such as girders may lead to the malfunction and even failure of the prestressed bridges that comprises more than 55% of all new and replaced bridges built in US between the year 2000 and 2012. Settlement of foundations supporting the bridge piers and abutments impairs the superstructure integrity and serviceability of the bridge, or even collapses the bridge if the settlement is over a certain limit. In present study, the dynamic interaction between vehicles and the bridges subjected to prestress force loss and foundation settlement has been investigated. Based on modal superposition technique and principal of virtual works, new bridge-vehicle interaction models have been created to take the effects of prestress and foundation settlement on dynamic bridge and vehicle responses into account. With the developed models, numerical simulations have been performed to show that the prestress force makes the distribution of impact factors along the bridge unbalanced and the existence of foundation settlement may couple with road surface roughness of the bridge deck to possess an aggregated overall effect amplifying the bridge responses. In general, the vehicle responses are vulnerable to the prestress force loss and foundation settlement, which harms the riding comfort of passengers. The existed direct and indirect methods used for prestress loss identification are all based on the measurement collected from sensors deployed on the outside or inside of the bridge, which is not only costly but also inconvenient. The current study proposes to detect the prestress force loss of the bridge through the analysis of vehicle responses. Through simulations, it is found that light, low-frequency vehicles moving at low speeds have a better performance in detecting the bridge prestress loss than the heavy, high-frequency vehicles with high speeds. The advantage of the proposed method is that it only needs a few sensors installed on the vehicle, and works without interrupting the ongoing traffic, which is efficient and cost-effective.

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17

Walker, John Griffith. "Investigation of induced strain actuator patches implementing modeling techniques and design considerations to reduce critical stress." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03042009-040453/.

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18

Zhang, Zhiming. "An Integrated System for Road Condition and Weigh-in-Motion Measurements using In-Pavement Strain Sensors." Diss., North Dakota State University, 2016. http://hdl.handle.net/10365/25819.

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The United States has the world?s largest road network with over 4.1 million miles of roads supporting more than 260 million of registered automobiles including around 11 million of heavy trucks. Such a large road network challenges the road and traffic management systems such as condition assessment and traffic monitoring. To assess the road conditions and track the traffic, currently, multiple facilities are required simultaneously. For instance, vehicle-based image techniques are available for pavements? mechanical behavior detection such as cracks, high-speed vehicle-based profilers are used upon request for the road ride quality evaluation, and inductive loops or strain sensors are deployed inside pavements for traffic data collection. Having multiple facilities and systems for the road conditions and traffic information monitoring raises the cost for the assessment and complicates the process. In this study, an integrated system is developed to simultaneously monitor the road condition and traffic using in-pavement strain-based sensors, which will phenomenally simplify the road condition and traffic monitoring. To accomplish such a superior system, this dissertation designs an innovative integrated sensing system, installs the integrated system in Minnesota's Cold Weather Road Research Facility (MnROAD), monitors the early health conditions of the pavements and ride quality evaluation, investigates algorithms by using the developed system for traffic data collection especially weigh-in-motion measurements, and optimizes the system through optimal system design. The developed integrated system is promising to use one system for multiple purposes, which gains a considerable efficiency increase as well as a potential significant cost reduction for intelligent transportation system.
USDOT (U.S. Department of Transportation)
MPC (Mountain-Plains Consortium)

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19

Penketgorn, Thiwa. "Load and resistance factor design for wood structures." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/104535.

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20

Hsia, Wei-Kung 1958. "DOUBLE ANGLE CONNECTION MOMENTS (RICHARD EQUATION, PRYING FORCE, BEAM-LINE THEORY, MOMENT ROTATION CURVE)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/291892.

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21

Tharayil, Pradeep Ambareeksh, and Mohammadali Baradaran. "HPDC Die design for Additive Manufacturing : Simulation and Comparison of Thermal Stresses in HPDC die designed for Additive Manufacture." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell produktutveckling, produktion och design, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-43319.

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Additive manufacturing has a great potential to benefit die manufacture by shortening the lead time considerably and lifting the limitations on design complexity imposed by conventional manufacturing techniques. However, AM has its own requirements that together are known as Design for Additive Manufacturing and account for the process limitations. One of the significant requirements is mass efficiency of the design (it should be as light as possible). If it’s not fulfilled, AM won’t be able to make an economical solution or substitution despite having outstanding benefits. The present investigation has been framed with respect to such concern. This investigation attempts to draw a comparison between the performance of two design variants. Additionally, it has been tried to study the employed method, document implementation of the approach, and identify the challenges in accordance with design for additive manufacturing. Simulation of thermal stresses generated in die inserts for a given component during one cycle of high pressure die casting is presented. Initial design of the die inserts is subjected to redesign with the intention of mass reduction by incorporating honeycomb structure. Temperature evolution and resultant thermal stresses are analyzed for redesign and compared to those of original design. Simulation of high pressure die casting was carried out in MagmaSoft to obtain temperature history of die inserts and cast. Implicit nonlinear elastic fully coupled thermal displacement model was setup in Abaqus in which Magma results were used as input for stress calculation. Results show that according to our specific design, HPDC die with thin walled feature cannot withstand the thermal and mechanical load. However, with iterative analysis and proper topology optimization, a lightweight complex geometry die can be successfully made.

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22

Terdalkar, Sachin Sharad. "Graphically driven interactive stress reanalysis for machine elements in the early design stage." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0818103-192248.

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Thesis (M.S.)--Worcester Polytechnic Institute.
Keywords: Stress Analysis; Machine Design; Combined Approximation Reanalysis; Structural Reanalysis; Design Process; FEM; Finite Element Analysis. Includes bibliographical references (p. 88-97).

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23

Cross, Benjamin Thomas. "Analysis of the AASHTO fatigue design provisions for welded steel bridge details using reliability theory." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 101 p, 2007. http://proquest.umi.com/pqdweb?did=1338919111&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Hwa, Ken. "Toward advanced analysis in steel frame design." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765960991&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1209158261&clientId=23440.

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25

Guler, Erdogan. "A Methodology For Lining Design Of Circular Mine Shafts In Different Rock Masses." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615662/index.pdf.

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The objective of this thesis is to predict lining thickness inside circular mine shafts. A numerical study with different rock mass strengths and different in-situ non-hydrostatic stresses are carried out in 2D shaft section models to predict pressures that develop on lining support. An iterative process of applying support pressure until observing no failure zone around shaft is used to simulate lining support pressure for each individual model. Later, regression and fuzzy logic analyses are carried out to find a pressure equation for all of the models. Finally, the pressure equation derived is used in elastic &ldquo
thick-walled cylinder&rdquo
equation to calculate the lining thickness required to prevent the development of a failure zone around shafts. At the end of this research, a computer program &ldquo
Shaft 2D&rdquo
is developed to simplify the lining thickness calculation process.

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26

Paul, Jai P. "Sensitivity analysis of design parameters for trunnion-hub assemblies of bascule bridges using finite element methods." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001157.

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27

Mason, Michael A. "A PRACTICAL TOOL FOR THE DETERMINATION OF SURFACE STRESSES IN RAILROAD BEARINGS WITH DIFFERENT CONTACT GEOMETRIES AND LOAD CONDITIONS USING FINITE ELEMENT ANALYSIS." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3663.

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The connection between contact geometry and fatigue in tapered roller bearings utilized in the railroad environment is still of interest. Roller bearings for railroad applications are typically precision ground with crowned contact geometries to prevent edge loading of components. This normally results in completely elastic Hertzian contact stresses under standard railcar loads. However, under extreme load conditions, detrimental edge loading has been known to occur. It is proposed to develop a tool, using finite element analysis, that can be utilized to optimize complex raceway crown geometries for severe applications. A successful implementation of this tool is presented and validated using proven Hertzian contact theory. Correlation within 5% of the ultimate surface and subsurface stress magnitudes, using finite element modeling, in contrast with proven contact theory is achieved. In addition, analyses of other load conditions and contact geometries in order to illustrate the practical application of the tool are exhibited.

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Mahaarachchi, Dhammika. "Behaviour and design of profiled steel cladding systems subject to pull-through failures." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15875/1/Dhammika_Mahaarachchi_Thesis.pdf.

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The common profiled steel cladding systems used in Australia and its neighboring countries are made of very thin (0.42 mm) high strength steel (G550 with a minimum yield stress of 550 MPa) and are crest-fixed. However, these claddings often suffer from local pull-through failures at their screw connections during high wind events such as storms and cyclones. Past experience and researches have shown that the loss of steel roofs has often occurred due to local pull-through failures of their screw connections under uplift or suction loading. Loss of claddings always led to a progressive collapse of the entire building. This situation is continuing because of the lower priority given to the design of roof and wall cladding systems. At present, steel design codes do not provide guidelines for the design of crest-fixed steel roof or wall claddings. Past research has shown that European and American recommendations for steel claddings cannot be used for Australian crest-fixed cladding systems as they were developed mainly for valley-fixed claddings subjected to gravity loading instead of crest-fixed claddings subjected to wind uplift/suction loading. Therefore at present the design of thin steel cladding systems is based on laboratory tests and is expensive. These situations inhibit the innovative design and advances in the steel cladding industry. Since the local pull-through failures in the less ductile G550 steel claddings are initiated by transverse splitting at the fastener hole, analytical studies have not been able to determine the pull-through failure loads accurately. Therefore in the first stage of this research an appropriate fracture/splitting criterion was developed using a series of large scale and small scale experiments of crest-fixed steel claddings. A shell finite element model of crest-fixed steel cladding was then developed that included the new fracture/splitting criterion and advanced features such as hyperelastic material modelling, contact simulations, residual stresses and geometric imperfections. The improved finite element analyses were able to model the pull-through failures associated with splitting as evident from the comparison of their results with the corresponding full-scale experimental results. An extensive series of parametric studies considering the effects of material properties and geometric parameters of the two commonly used trapezoidal cladding profiles was undertaken using finite element analysis. Appropriate design formulae for the pull-through and dimpling failure load of trapezoidal profiles were then derived for optimization purposes and to simplify the current design method. This will then lead to modification and optimisation of cladding profiles to satisfy the requirements of both strength (safety during cyclones and storms) and economy. This thesis presents the details of large scale experimental studies undertaken and the results including the criterion for the splitting/fracture failure of high strength steel cladding systems. It describes the many advances made in the finite element modelling of crest-fixed steel cladding systems including the effects of localised pull-through and dimpling failures. Finally, it presents a simple design method for trapezoidal steel cladding systems under wind uplift or suction loading.

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Mahaarachchi, Dhammika. "Behaviour and Design of Profiled Steel Cladding Systems Subject to Pull-through Failures." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15875/.

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The common profiled steel cladding systems used in Australia and its neighboring countries are made of very thin (0.42 mm) high strength steel (G550 with a minimum yield stress of 550 MPa) and are crest-fixed. However, these claddings often suffer from local pull-through failures at their screw connections during high wind events such as storms and cyclones. Past experience and researches have shown that the loss of steel roofs has often occurred due to local pull-through failures of their screw connections under uplift or suction loading. Loss of claddings always led to a progressive collapse of the entire building. This situation is continuing because of the lower priority given to the design of roof and wall cladding systems. At present, steel design codes do not provide guidelines for the design of crest-fixed steel roof or wall claddings. Past research has shown that European and American recommendations for steel claddings cannot be used for Australian crest-fixed cladding systems as they were developed mainly for valley-fixed claddings subjected to gravity loading instead of crest-fixed claddings subjected to wind uplift/suction loading. Therefore at present the design of thin steel cladding systems is based on laboratory tests and is expensive. These situations inhibit the innovative design and advances in the steel cladding industry. Since the local pull-through failures in the less ductile G550 steel claddings are initiated by transverse splitting at the fastener hole, analytical studies have not been able to determine the pull-through failure loads accurately. Therefore in the first stage of this research an appropriate fracture/splitting criterion was developed using a series of large scale and small scale experiments of crest-fixed steel claddings. A shell finite element model of crest-fixed steel cladding was then developed that included the new fracture/splitting criterion and advanced features such as hyperelastic material modelling, contact simulations, residual stresses and geometric imperfections. The improved finite element analyses were able to model the pull-through failures associated with splitting as evident from the comparison of their results with the corresponding full-scale experimental results. An extensive series of parametric studies considering the effects of material properties and geometric parameters of the two commonly used trapezoidal cladding profiles was undertaken using finite element analysis. Appropriate design formulae for the pull-through and dimpling failure load of trapezoidal profiles were then derived for optimization purposes and to simplify the current design method. This will then lead to modification and optimisation of cladding profiles to satisfy the requirements of both strength (safety during cyclones and storms) and economy. This thesis presents the details of large scale experimental studies undertaken and the results including the criterion for the splitting/fracture failure of high strength steel cladding systems. It describes the many advances made in the finite element modelling of crest-fixed steel cladding systems including the effects of localised pull-through and dimpling failures. Finally, it presents a simple design method for trapezoidal steel cladding systems under wind uplift or suction loading.

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Filomeno, Coelho Rajan. "Multicriteria optimization with expert rules for mechanical design." Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211184.

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Though lots of numerical methods have been proposed in the literature to optimize me-chanical structures at the final stage of the design process, few designers use these tools since the first stage. However, a minor modification at the first step can bring significant change to the global performances of the structure. Usually, during the initial stage, models are based on theoretical and empirical equations, which are often characterized by mixed variables: continuous (e.g. geometrical dimensions), discrete (e.g. the cross section of a beam available in a catalogue) and/or integer (e.g. the number of layers in a composite material). Furthermore, the functions involved may be non differentiable, or even discontinuous. Therefore, classical algorithms based on the computation of sensi-tivities are no more applicable.

Consequently, to solve these problems, the most wide-spread meta-heuristic methods are evolutionary algorithms (EAs), which work as follows: the best individuals among an initial population of randomly generated potential solutions are favoured and com-bined (by specific operators like crossover and mutation) in order to create potentially better individuals at the next generation. The creation of new generations is repeated till the convergence is reached. The ability of EAs to explore widely the design space is useful to solve single-objective unconstrained optimization problems, because it gener-ally prevents from getting trapped into a local optimum, but it is also well known that they do not perform very efficiently in the presence of constraints. Furthermore, in many industrial applications, multiple objectives are pursued together.

Therefore, to take into account the constrained and multicriteria aspects of optimization problems in EAs, a new method called PAMUC (Preferences Applied to MUltiobjectiv-ity and Constraints) has been proposed in this dissertation. First the user has to assign weights to the m objectives. Then, an additional objective function is built by linearly aggregating the normalized constraints. Finally, a multicriteria decision aid method, PROMETHEE II, is used in order to rank the individuals of the population following the m+1 objectives.

PAMUC has been validated on standard multiobjective test cases, as well as on the pa-rametrical optimization of the purge valve and the feed valve of the Vinci engine, both designed by Techspace Aero for launcher Ariane 5.

\
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished

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Garapati, Sri Harsha. "Analysis of single fiber pushout test of fiber reinforced composite with a nonhomogeneous interphase." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0002951.

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Garapati, Sriharsha. "Analytical and Numerical Modeling of Assembly Procedures of Steel Fulcra of Bascule Bridges." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4490.

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To model shrink-fitting in metal components, an analytical model for two long compound cylinders with temperature dependent material properties and interference between them is developed for calculating transient temperatures and stresses. A finite element model is developed for the same geometry which incorporated the temperature dependent material properties. A convergence study is performed on the finite element and analytical model. The finite element model is validated by comparing the approximations of finite element model with the analytical solution. In an assembly procedure of fulcrums for bascule bridges, called AP1, the trunnion is shrink-fitted into a hub, followed by shrink fitting the trunnion-hub assembly into the girder of the bridge. In another assembly procedure called AP2, the hub is shrink-fitted into the girder, followed by shrink-fitting the trunnion in the hub-girder assembly. A formal design of experiments (DOE) study is conducted on both AP1 and AP2 using the finite element model to find the influence of geometrical parameters such as radial thickness of the hub, radial interference, and various shrink-fitting methods on the design parameter of overall minimum critical crack length (OMCCL) - a measure of likelihood of failure by cracking. Using the results of DOE study conducted on both the assembly procedures, AP1 and AP2 are quantitatively compared for the likelihood of fracture during assembly. For single-staged shrink-fitting methods, for high and low hub radial thickness to hub inner diameter ratio, assembly procedure AP1 and AP2 are recommended, respectively. For fulcra with low hub radial thickness to hub inner diameter ratio and where staged shrink-fitting methods are used, for AP2, cooling the trunnion in dry-ice/alcohol and heating the girder, and for AP1, cooling the trunnion-hub assembly in dry-ice/alcohol followed by immersion in liquid nitrogen is recommended. For fulcra with high hub radial thickness to hub inner diameter ratio and where staged shrink-fitting methods are used, cooling the components in dry-ice/alcohol and heating the girder is recommended for both AP1 and AP2. Due to the limitations of AP2, assembly procedures by heating the girder with heating coils instead of dipping an already stressed trunnion-hub assembly in liquid nitrogen are studied for decreasing the likelihood of failure by cracking and yielding. In an assembly procedure called AP3-A, only the girder is heated to shrink-fit the trunnion-hub assembly in the girder. This assembly procedure AP3-A is found to be infeasible because the girder fails by yielding if heating is expected to be completed in a reasonable amount of time. An alternative assembly procedure called AP3-B is suggested for shrink-fitting where the heating of the girder is combined with cooling the trunnion-hub assembly in dry-ice/alcohol mixture. This assembly procedure AP3-B is found to be feasible. A complete DOE study is conducted on AP3-B to find the influence of parameters like hub radial thickness and radial interference at trunnion-hub interface on the design parameter of overall minimum critical crack length. The design parameter, OMCCL values during the assembly procedure AP3-B are quantitatively compared with the widely used assembly procedures (AP1 single-stage shrink-fitting and AP1 multi-staged shrink fitting). The results of this work suggest that increasing the hub radial thickness decreases the likelihood of fracture significantly. For hubs with large radial thickness, heating the girder combined with cooling the trunnion-hub in dry-ice/alcohol mixture (AP3-B) is recommended but for hubs with low radial thickness, multistage cooling of the trunnion-hub assembly in dry-ice/alcohol mixture followed by dipping in liquid nitrogen (AP1- multistage cooling) is recommended.

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Панченко, Д. О., and Блащук Н. В. "Переривчасті стрічкові фундаменти." Thesis, ВНТУ, 2018. http://ir.lib.vntu.edu.ua//handle/123456789/20972.

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Розглянуто ефективні конструкції стрічкових фундаментів мілкого закладання, а саме переривчасті стрічкові фундаменти. Оцінено позитивні і негативні сторони цього їх використання.
Effective constructions of narrow foundation foundations of tape, namely, intermittent ribbon foundations, are considered. Positive and negative aspects of their use are assessed.

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Diercks, David Robert. "Measurement of Lattice Strain and Relaxation Effects in Strained Silicon Using X-ray Diffraction and Convergent Beam Electron Diffraction." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3978/.

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The semiconductor industry has decreased silicon-based device feature sizes dramatically over the last two decades for improved performance. However, current technology has approached the limit of achievable enhancement via this method. Therefore, other techniques, including introducing stress into the silicon structure, are being used to further advance device performance. While these methods produce successful results, there is not a proven reliable method for stress and strain measurements on the nanometer scale characteristic of these devices. The ability to correlate local strain values with processing parameters and device performance would allow for more rapid improvements and better process control. In this research, x-ray diffraction and convergent beam electron diffraction have been utilized to quantify the strain behavior of simple and complex strained silicon-based systems. While the stress relaxation caused by thinning of the strained structures to electron transparency complicates these measurements, it has been quantified and shows reasonable agreement with expected values. The relaxation values have been incorporated into the strain determination from relative shifts in the higher order Laue zone lines visible in convergent beam electron diffraction patterns. The local strain values determined using three incident electron beam directions with different degrees of tilt relative to the device structure have been compared and exhibit excellent agreement.

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Crane, Charles Kennan. "Shear and shear friction of ultra-high performance concrete bridge girders." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34745.

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Ultra-High Performance Concrete (UHPC) is a new class of concrete characterized by no coarse aggregate, steel fiber reinforcement, low w/c, low permeability, compressive strength exceeding 29,000 psi (200 MPa), tensile strength ranging from 1,200 to 2,500 psi (8 to 17 MPa), and very high toughness. These properties make prestressed precast UHPC bridge girders a very attractive replacement material for steel bridge girders, particularly when site demands require a comparable beam depth to steel and a 100+ year life span is desired. In order to efficiently utilize UHPC in bridge construction, it is necessary to create new design recommendations for its use. The interface between precast UHPC girder and cast-in-place concrete decks must be characterized in order to safely use composite design methods with this new material. Due to the lack of reinforcing bars, all shear forces in UHPC girders have to be carried by the concrete and steel fibers. Current U.S. codes do not consider fiber reinforcement in calculating shear capacity. Fiber contribution must be accurately accounted for in shear equations in order to use UHPC. Casting of UHPC may cause fibers to orient in the direction of casting. If fibers are preferentially oriented, physical properties of the concrete may also become anisotropic, which must be considered in design. The current research provides new understanding of shear and shear friction phenomena in UHPC including: *Current AASHTO codes provide a non-conservative estimate of interface shear performance of smooth UHPC interfaces with and without interface steel. *Fluted interfaces can be created by impressing formliners into the surface of plastic UHPC. AASHTO and ACI codes for roughened interfaces are conservative for design of fluted UHPC interfaces. *A new equation for the calculation of shear capacity of UHPC girders is presented which takes into account the contribution of steel fiber reinforcement. *Fibers are shown to preferentially align in the direction of casting, which significantly affects compressive behavior of the UHPC.

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Nezamian, Abolghasem 1968. "Bond strength of concrete plugs embedded in tubular steel piles." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/5601.

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37

Dasgupta, Mitul. "Design Against Stress: Design's methodological approach of dealing with the issue of stress." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282317515.

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Uggla, Gabriel. "Pause — Stress Management." Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171773.

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Stress affects us all more or less, but over the last decade people who suffer from severe stress and its symptomshas increased considerably. Women are especially affected, with absence from Swedish workplaces due tostress growing 370% between 2011—2019. As of 2020, stress is treated when we experience symptoms suchas anxiety, panic attacks or insomnia, but it is more sustainable to prevent stress than treating it in terms ofmoney, time, health and effort.Through collaboration with people affected by stress, psychiatrists & researchers specialized on stress, anddesigners from different disciplines, the topic of stress was explored and researched to create a conceptualsolution that could be able to help users manage their stress better.“Pause” is the result of this work. It is a conceptual product ecosystem consisiting of an application andwatch that facilitates monitoring and management of stress in day-to-day scenarios, in order to prevent andreduce stress.

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39

Novotný, Lukáš. "Návrh a realizace experimentálního zařízení pro určování zbytkové napjatosti ohýbaných vzorků." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382570.

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The master thesis is focused to design and realization of experimental equipment for researching of residual stress determination for specimen with non-uniform distribution stress along the depth. Literature search study of problematic was performed and it was used for elaboration of chapters about origin of residual stress, their classification and chapters about methods, which are used for measuring of residual stress and their determination. The following part explains the design of experimental equipment and stress-strain analysis of selected parts of this equipment. Then the final design of equipment is presented, including complete production drawings, and it’s explained final assembling of experimental equipment. Final chapter is devoted to examinable loading of specimen.

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Cheng, Wentao. "In-plane shrinkage strains and their effects on welding distortion in thin-wall structures." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124049585.

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Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xx, 268 p.; also includes graphics (some col.). Includes bibliographical references (p. 256-268). Available online via OhioLINK's ETD Center

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Engelsen, Frode. "Design-oriented gust stress contraints for aeroservoelastic design synthesis /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/9965.

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Wang, Tianyi. "International students’ stress : Innovation for health-care service." Thesis, Linnéuniversitetet, Institutionen för design (DE), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-76296.

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With the trend of increasing international academic exchange, the number of international students in Sweden continues to expand over years. The stress faced by international students has attracted more and more attention from university organizations and the society. This project takes the current mental health-care service for international students at Linnaeus University as the research object. Based on the participatory design and service design theory, challenges faced by the international student health-care service system and improvement opportunities were investigated through a stakeholder map, semi-structured interviews, observations, questionnaires and co-creation workshops among other methods. By introducing participatory design into the development process, an improved mental health-care service system with integrated online and offline information is presented as an example for universities’ organizations for improving the mental health-care service for international students.

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Puidokas, Sabrina Michelle [Verfasser]. "Design of Highly Stressed Brazed Joints / Sabrina Michelle Puidokas." Aachen : Shaker, 2013. http://d-nb.info/1049384210/34.

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Jacobsson, Malin. "A Stress Free Workplace : Spatially planned office space to diminish environmental stress." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-20007.

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The main objective of this thesis was to understand the environmental variables that affect humans psychological states when it comes to stress. More specifically, the environmental variables at the company Maintpartner AB's new Swedish headquarters office in Årsta, Stockholm, a company concentrated on customized industrial maintenance and operation service. In my thesis I found evidence that open-plan solutions would be a stressor due to increase disturbance from coworkers. Open-plan offices could also be perceived as a stressor because of the limitation in personal control. Through implementing nature and/or integrating it via visual escape the space could be perceived as more attractive and less crowded. Maintpartner AB's administrative personnel has highly individual work tasks and therefore a need for customized workplaces. This resulted in a design concept with separated office rooms, individually designed to meet the staffs individual need. Some areas are designed to work as meeting areas for work or social related encounters

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Eriksson, Alexander, and Veronica Flykt. "Concrete floor : Design of prefabricated pre-stressed hollow core slabs with verification through PRE-Stress and comparison with site-cast slab." Thesis, KTH, Byggteknik och design, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279158.

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The most common prefabricated concrete slabs are hollow core slabs, which are usually pre-tensioned. How to design these parts is not compiled today in a manual where it is clear how this is done, this knowledge is generally classified as expert knowledge. The purpose was to bring forth how to design prefabricated pre-stressed hollow core slabs, HD/F, and then create a design aid that is compared by hand calculations with the PRE-Stress design program from StruSoft. Furthermore, to compare it with site-cast concrete slabs to see differences in the amount of material and the thickness of the structure under the same conditions.The design aid is not complete as some limitations had to be made. When it comes to results, the hand calculations in comparison with PRE-Stress have not resulted in identical answers but have proven to be on the safe side consistently through the design, which indicates that the design aid is fully functional. In the comparison with site-cast concrete slabs, it can be noted that prestressed hollow core slabs require less concrete volume, slimmer construction, and longer span widths but greater reinforcement volume.
Det vanligaste prefabricerade betongbjälklaget är håldäcksplattor som oftast är spännarmerade. Hur man dimensionerar dessa bärverksdelar finns idag inte samlat i en handbok där det står tydligt hur man gör, den kunskapen klassas generellt som expertiskunskap. Syftet var att ta fram hur man dimensionerar prefabricerade förspända håldäcksplattor, HD/F, och sedan skapa ett dimensioneringshjälpmedel som jämförs genom handberäkningar med PRE-Stress dimensioneringsprogram från StruSoft. Vidare genomfördes jämförande beräkningar för platsgjutet betongbjälklag för att se skillnader i materialmängd och konstruktionstjocklek under samma förutsättningar.Dimensioneringshjälpmedlet är inte komplett då vissa avgränsningar behövts göras. När det kommer till resultat har handberäkningar i jämförelse med PRE-Stress inte resulterat i identiska svar, men visat sig hamna på säkra sidan konsekvent genom dimensioneringen vilket tyder på att dimensioneringshjälpmedlet är fullt användbart. I jämförelsen med platsgjutet bjälklag kan man konstatera att förspända håldäcksplattor ger mindre betongvolym, slankare konstruktion och längre spännvidder men större armeringsmängd.

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Kehler, Charlotte. "Stressa-Mindre - En studie om offentlig amning." Thesis, Malmö universitet, Fakulteten för kultur och samhälle (KS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-22970.

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I denna studien undersöktes det om det går att använda produktdesign för att minska stressen för mammor vid offentlig amning. Syftet med studien var att hjälpa mammor att stressa ned och målet var att ta fram ett designförslag i form av en produkt för att uppfylla syftet.För att kunna lyckas med detta har användarcentrerad design legat till grund. Metoderna som använts är intervju, observation och enkät, och dessa gjordes på målgruppen nyblivna mammor. Vidare har studien krävt en marknadsundersökning för att se vilka produkter som redan existerar på marknaden. Även normkreativ design har använts för dels att uppmärksamma vilka problem som kan uppstå vid offentlig amning och samtidigt rikta kritik mot samhället för de alltför utbredda attityder om amning och dels för att föra studien framåt med hjälp av idégenereringar. Slutsatsen är, att det att behöva visa sig inför andra är den största orsaken till stress för mammorna vid amning. Självklart känner inte alla mammor så, men enligt flertalet av respondenterna i denna studien var detta deras största bekymmer när de vistades i andra miljöer än hemmet. Slutprodukten är ett designförslag på hur detta problemet skulle kunna lösas. Då alla individer är olika och har olika krav och åsikter kan inte en produkt behövas till alla, men enligt studien finns det en målgrupp för produkten.
This study examines whether product design can be used to reduce the stress for mothers during public breastfeeding. The purpose of the study was to help mothers to stress down, and the goal was to produce a design proposal in the form of a product with the purpose to succeed in this.In order to succeed, user-centered design has been the basis for the used methods, utilizing interviews, observations and questionnaires. this have been performed on the target group consisting of new mothers. Furthermore, the study has required a market research to see which products already exist on the market. Norm creativity design has also been used to pay attention to the problem of public breast-feeding and to criticize the society regarding the current attitudes on this, but also to help progression of the study by creation of ideas.In conclusion the biggest cause of stress for the mothers during public breastfeeding is having to bare yourself in the company of others. Of course, it is not a problem for all mothers, but in this study the majority of the respondents on whom the study is based, had dread of this. The end product is a design proposal on how this problem could be solved. Since all individuals are different, have different requirements and opinions, not all are in need of such a product, but according to the study there is a target group needing such help.

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Adnan, Md Asif, and Ahmed Shehata. "Stress Analysis Validation for Gear Design." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-16862.

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Gear stress analysis and understanding the effect of misalignment and microgeometry is important for gear designers and for those who work in gear maintenance. The misalignment can lead to the higher stress acting in one side of the gear tooth and the micro-geometry modification can improve the stress distribution in the gear teeth. In this research, a helical gear pair was modeled using three different software and tools; LDP, KISSsoft and Abaqus. Three different cases were modeled to study the effect of misalignment and microgeometry. Finally, the results from different tools were presented and discussed. It was observed that the tooth contact analysis software resulted in significantly higher stresses than the FE software. The results have been discussed to understand the differences in the cases obtained from the used tools. The results showed how bad is the effect of the misalignment on the gear mesh and the stress distribution and how the microgeometry modifications are used to compensate that effect.

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48

Hopkinson, David P. "Development of stress gradient enhanced piezoelectric composite unimorph actuators." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/16372.

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Falkirk, Isabella. "Under Pressure." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20701.

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Under pressure is an expression of stress. It is about work becoming everything. It is about not being able to separate your self from your work. It is about carrying the office with you all the time.The result is a well kept together collection of garments ranging from commercial to experimental on the edge of not being wearable.
Program: Modedesignutbildningen

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50

Valdivia, Sharon. "Harmoni - more than just a lamp." Thesis, Linnéuniversitetet, Institutionen för design (DE), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-67150.

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Abstract:

In this thesis, I wanted to design a lamp in collaboration with the lighting company Örsjö Belysning AB, that would contribute to stress-reduction and calmness both through visual and functional aspects. My focus in the study and the design process was on the lamps shape and light, where my primary inspiration was taken from the qualities of water. My lamp also had to fit into Örsjö Belysnings current assortment. My research showed that rounded shapes and adjustable light are two important factors for producing calmness and well-being for the user. The result of my work was a lamp with the name Harmoni. A LED floor lamp made of brass metal and acrylic plastic, with focus on rounded shapes, lightness, flexibility and symmetry. The lamp has a unique and adjustable light emission, that gives two different kinds of light from the same source. It functions both as a floor and a wall lamp in one.

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Dissertations / Theses on the topic 'Design stresses'

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