This thesis is concerned with the optimalization of suspension arm desing in term of rigidity wheel direction and weight.

This thesis is concerned with Semi-trailing arm suspension on racing car Škoda 130RS of group V. Kinematic analysis of suspension has been performed as well as stress analysis of single parts. On basis of these analysis, suspension design has been created. Design of suspension and fixtures are solved with regard to simplicity of manufacture, reduction of weight and reduction of maximal stresses. Adjustment of geometry of suspension (toe and camber) is realised by changing the position of fixtures on the body.

Denna rapport omfattar utveckling av en rigg för att testa slitage av däck. Detta sker genom omkonstruktion av existerande pinne-på-skivatribometer rigg som man finner hos Kungliga Tekniska Högskolan. Pinne-på-skivatribometer även känd som tribometer, används för att undersöka hur olika material interagerar med varandra genom glidning, rullning eller kombination av dessa två. Mikropartiklarna som skapas vid slitage av däck och de effekter det har på sin omgivning är förfarande i bred utsträckning okända. Partiklarna från däckslitage uppskattas bidra till minst hälften av de mikroplaster som hamnar i vår omgivning. För att utöka kunskaperna om detta så testar man hur däck slits under olika driftförhållanden. Att testa i full skala med riktiga fordon på testbana är dyrt och ger inte samma kontroll över parametrar som i en testrigg som befinner sig i en kontrollerad miljö. En konstruktion som uppfyller uppdragsgivarens krav och önskemål har skapats i form av en CAD modell. Konstruktionen är en modifikation av pinne-på-skivatribometer testriggen och använder sig i stor utsträckning av komponenter från radiostyrda bilar samt andra vanliga standardkomponenter. Ett viktigt krav som uppfylldes var att kunna ändra vinkel på däcket, så att man också kan testa kantkontakten. / This report covers the development of a rig for testing tire wear. This is done by redesigning the existing pin-on-disc tribometer rig that can be found at the Royal Institute of Technology. Pin-on-disc tribometer also known as a tribometer, is used to investigate how different materials interact with each other through sliding, rolling, or a combination of the two. The microparticles that are created during tire wear and the effects they have on their surroundings are largely unknown. The particles from tire wear are estimated to contribute to at least half of the microplastics that end up in our environment. To expand knowledge about this, they test how tires wear under different operating conditions. Full-scale testing with real vehicles on a test track is expensive and does not provide the same control over parameters as in a test rig that is in a controlled environment. A construction that meets the client's requirements and wishes has been created in the form of a CAD model. The design is a modification of the pin-on-disc tribometer test rig and makes extensive use of components from radio-controlled cars as well as other common standard components. An important requirement that was met was being able to change the angle of the tire so that you can also test the edge contact.

The objectives of the research presented in this thesis are the development of a seven degree-of-freedom morphing airplane and the design and integration of a variable camber compliant tail. The morphing airplane was designed and manufactured to study the benefits of large planform changes and flight control morphing. Morphing capabilities of each wing consist of 8 in. wing extension and contraction, 40° of wing sweep and ±20.25° of outboard wing twist in addition to 6 in. of tail extension and contraction. Initial wind-tunnel tests proved that for a large range of lift coefficients, the optimal airplane configuration changes to minimize the drag. Another portion of this research deals with the development of a structural optimization program to design a variable camber compliant tail. The program integrates ANSYS, aerodynamic thin airfoil theory and the Method of Moving Asymptotes to optimize the shape of an airfoil tail for maximum trailing edge deflection. An objective function is formulated to maximize the trailing edge tip deflection subject to stress constraints. The optimal structure needs to be flexible to maximize the tip deflection, but stiff enough to minimize the deflection of the tip due to aerodynamic loading. The results of the structural optimization program created a compliant tail mechanism that can deflect the trailing edge tip with a single actuator ±4.27°. / Master of Science

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The use of high compressive strengths in prestressed bridge girders can lower costs by allowing for longer spans, increased girder spacing, and smaller cross-sections. If high strength lightweight concrete (HSLWC) is used, these advantages are further enhanced due to the corresponding reduction in self-weight. Additional benefits can then be realized in the form of more traffic lanes, increased load capacity, smaller substructures, reduced crane capacity requirements, and lower shipping costs. Despite the possible economic savings, HSLWC has been used infrequently in prestressed bridge girder applications across the nation. While recent research has been performed to extend the applicability of current bridge design specifications to normal weight concretes with strengths as high as 18 ksi, little has been done by comparison with regards to HSLWC. The purpose of the research in this report was to assess whether current bridge design specifications for transfer length, development length, prestress loss, camber, and flexural capacity are satisfactory for use with fully-bonded, pretensioned flexural members consisting of HSLWC and to make recommendations for improvements where necessary. Twelve high strength pretensioned beams of variable unit weight (eight lightweight beams and four normal weight beams) and strand size (eight beams with 0.5-in. strand and four beams with 0.6-in. strand) were cast at the Thomas M. Murray Structural Engineering Laboratory at Virginia Tech. These beams were allowed to sit for a period of several months after fabrication while measurements were taken regarding transfer length, prestress loss, and camber. After this period, the beams were load tested to collect development length data, flexural data, and further data related to prestress loss. In addition to the laboratory cast beams, prestress loss and camber data from six full-size bridge beams (five lightweight beams and one normal weight beam) cast as part of a separate project at Virginia Tech was examined. Analysis of the results for all beams shows that with a few caveats, the current AASHTO LRFD Specifications and other design methods examined regarding the topics under consideration are satisfactory for use in the design of HSLWC pretensioned bridge girders with properties similar to those of the beams studied. / Ph. D.

Prestressed concrete structural members camber upwards or downwards depending upon the location of application of prestress force. Identical members do not camber equally due to variability of the factors influencing it. Differential camber in the beams, if significant, results in excessively tall haunches or girder top flange extending into the bottom of the slab. For adjacent members like deck bulb-tees and box girders that are to be transversely post-tensioned the differential camber causes problems during the fit up process. This variation is undesirable and hinders the smooth progress of construction work if not properly accounted for at the design stage. Various factors influence camber and camber growth in prestressed members. Some of the factors are concrete strength and modulus, concrete creep and shrinkage properties, curing conditions, maturity of concrete at release of prestress force, initial strand stress, climatic conditions in storage and length of time in storage. Combinations of these variables result in variation of camber of otherwise similar beams at the time they are erected. One way to increase the precision of camber estimation is to use Monte Carlo simulation based upon the randomized parameters affecting the camber and camber growth. In this method, the parameters, in the form of a probability distribution function, are combined and passed through a deterministic model resulting in camber and camber growth prediction with narrowed probability bounds as compared to single definite value given by most contemporary methods. This outcome gives the expected range of cambers for a given girder design. After determining the expected range of camber, the ultimate goal is to provide guidelines for using unbonded monostrands for camber adjustment. / Master of Science