Welded structures susceptible to weld deformations require sequent processing to allow for mounting of precision components. This thesis includes a case study of the rear axle mount on a Volvo L220 wheel loader. A product development process was deployed in order to explore and evaluate alternative mounting methods such that manufacturing cost due to sequent processing could be decreased. Analysis of the frame variations showed any new concepts has to accommodate variations of up to $\delta z=-1.24\pm3.5$ mm. The product development process found two potential concept philosophies; transferring concepts which improves upon the current concept by transferring the processing away from the frame onto smaller components that are cheaper to process, and absorbing concepts that avoids sequent processing by absorbing the frame variations altogether. The transferring concept "Custom Plate" was selected for further development. The concept is based on the principals of reverse engineering by manufacturing a custom plate from a 3D surface map of the deformed mounting surface, placed between the frame and rear axle bridge, matching the surface geometry of both entities. The concept showed no apparent critical strength issues when simulated in CATIA V5. However, the economical gain of the concept is slim and depends heavily what spaces can be allocated for additional processing machinery. Suggestions for further development of the concept are given along with a discussion of improvements outside of the system boundary of the project, such as simulation of welds and welding sequence, and collection, storing, analysis, and visualisation of data.

Stora transportköpare visar ett stort intresse för att använda eldrivna lastbilar och på så sätt minska koldioxidutsläpp och främja en renare miljö. Detta medför en ökad förbrukning av elektrisk energi, vilket kräver expansion av elnäten för att klara av den ökade belastningen. Borås Elnät ansvarar för eldistributionen i centrala Borås och omkringliggande områden och vill undersöka hur expansion av elnätet kan påverkas av en ökad belastning från eldrivna tunga fordon. Syftet med denna projektrapport är att identifiera framtida laddningsbehov, påverkan på elnätet och eventuella åtgärder. Metoden bestod av tre delar för att ta fram resultatet. Först undersöktes nuläget gällande tungafordon i Viared, sedan nuläget för eldrivna lastbilar och till sist om nuvarande elnät kan hantera den eventuella extra belastning som kan tillkomma från eldrivna lastbilar. Tre framtidsscenarier studerades för att få fram den eventuella belastningen. Dessa framtidsscenarier baserades på fem, tio och tjugo år fram i tiden. Informationen inhämtades genom möten med företag och dialoger med branschaktörer, samt genom att studera befintlig forskning och litteratur. En uppskattad andel av eldrivna fordon i fordonsflottan togs fram med hjälp av tillgänglig information. Denna information användes för att utveckla en generell bild av framtiden för elektriska fordon i Viared. Resultatet pekar på en ökning av eldrivna fordon för samtliga tre scenarion där andelen eldrivna fordon i fordonsflottan ökar med tiden. Detta kan komma att påverka elnätet i Viaredgenom att den högsta förväntade strömmen som kan uppstå är högre än vad de nuvarande kablarna klarar. Toppeffekten som kan uppstå i transformatorstationen börjar också nå nivåer som kan peka på att åtgärder behöver göras. / Large transportation buyers show a great interest in using electric trucks to reduce carbondioxide emissions and promote a cleaner environment. This entails an increased consumption of electrical energy, which requires the expansion of electrical grids to handle the increased load. Borås Elnät is responsible for the electricity distribution in central Borås and surrounding areas and wants to investigate how the expansion of the electrical grid can be affected by an increased load from electric heavy vehicles. The purpose of this project report is to identify future charging needs, the impact on the electrical grid, and possible measures. The method consisted of three parts to obtain the results. First, the current situation regarding heavy vehicles in Viared was examined, then the current situation for electric trucks, and finally whether the existing electrical grid can handle the potential additional load from electric trucks. Three future scenarios were studied to determine the potential load. These scenarios were based on five, ten, and twenty years into the future. Information was gathered through meetings with companies and dialogues with industry stakeholders, as well as studying existing research and literature. An estimated share of electric vehicles in the vehicle fleet was determined using available information. This information was used to develop a general picture of the future of electric vehicles in Viared. The results indicate an increase in electric vehicles for all three scenarios, where the proportion of electric vehicles in the vehicle fleet increases over time. This may impact the electrical grid in Viared, as the highest expected current that can occur exceeds what the current cables can handle. The peak power that can occur at the transformer station is also reaching levels that may indicate the need for action.

Formula Student is a global engineering competition where university students collaborate to design, construct, and race formula-style cars. Aerodynamics is one aspect in the vehicle design that can improve on-track performance by increasing cornering and straight-line speed. To improve the aerodynamics of KTH Formula Student's DeV18 vehicle, the side structure is being redesigned. The current model, DeV17, features an underperforming tunnel-based side structure. To address this issue, this had the goal to investigate a new multi-element wing design that utilizes ground effect. The design study of the DeV18 vehicle is conducted using Siemens NX 2212 for 3D modelling and Simcenter Star-CCM+ 17.06.008-R8 for airflow simulations. To quickly investigate certain design parameters effect on the results, Design Manager Project inside Simcenter Star-CCM+ is used. The resulting side structure produces a total of 26 N of downforce and 6 N of drag at 40 kph, more than twice that of DeV17’s side structure while also producing less drag. Although this significant improvement compared to DeV17, it is believed that further increases in performance are necessary to compete with top teams. By using a more sophisticated method to optimize the multi-element wing, such as adjoint optimization, the concept could be improved. However, the overall potential of the concept is still considered too limited to achieve the desired performance goals, which is why it will no longer be investigated further.

The railway vehicles are an increasing mean of transportation due to, its reduced impact on environment and high level of comfort provided. These reasons have contributed to settle a positive perception of railway traffic into the European society. In this upward context, the railway industrial sector tackles some important challenges; maintaining low operational costs and controlling the nuisance by-products of trains operation, the most important being railway noise. Track dynamic plays a main role for both issues, since a significant part of the operational costs are associated with the track maintenance tasks and, the noise generated by the track can be dominant in many operational situations. This explains why prediction tools are highly valued by railway companies. The work presented in this licentiate thesis proposes methodologies for accurate and efficient modelling of railway track dynamics. Two core axes have led the development of this task, on one hand, the rail modelling and, on the other hand, the characterisation of the finite length nature of track supports. Firstly, concerning the rail modelling technique, it has evolved under two major premises. On one hand, regarding the frequency domain, it should describe high frequency behaviour of the rail. In order to accomplish with this first premise, a model based on Timoshenko beam theory is used, which can accurately account for the vertical rail behaviour up to 2500 Hz. On the other hand, with respect to the time domain, the response should be smooth and free of discontinuities. This last condition is fulfilled by implementation of the Timoshenko local deformation. Secondly, a model of support that considers its finite length nature is sought. For this purpose, a Timoshenko element over elastic foundation is formulated. Thus, the common model of support, which is based on a concentrated connection, is substituted by a distributed model of support. In this way, several enhancements are achieved; the temporal contact force response is smoothed and a more realistic shape is obtained, the amplitude of the displacement due to the parametric excitation is reduced and the magnitude associated to the ‘pin-pin’ frequency is not overestimated. / <p>QC 20170522</p>

oTUS is a Long Term Underwater Sensing, bottom landing, node for observations of ocean water temperatures. LoTUS measures temperature (moored to the seafloor) according to a spec-ified time schedule until, at the end of the mission, it surfaces to transmit the collected data to on shore recipients using an Iridium link. The paper presents an extension of the sensing capability to include water current velocity (speed and direction) using a robust, reliable and inexpensive Eulerian method. The method is based on the "tilting stick" principle where a combination of inertia measurement data and magnetic sensor data is used. The paper discusses the principal technique, the modeling of the system, practical considerations, and optimization of the setup for specific flow conditions along with verifying experimental data.

To keep up with technological as well as logistical challenges of the modern automobile market, major car manufacturing firms have resorted to virtual simulation tools. This enables the development as well as validation of vehicular models much before resources are invested into a new physical prototype.This project focuses on the development of a tool that would help in optimising the handling parameters of a vehicle. This is achieved by creating an optimization routine for tuning the various parameters of the Electronic Power Steering (EPAS). This process is usually done manually, by on-track testing, due to the difficulties in correlating Subjective Assessments (SA) with Objective Metrics (OM). Automating this process would help to reduce the overall research and development time, by providing a baseline tune for the EPAS parameters which could then be finely tweaked by manual track testing.The tool is built by interfacing various software in a multi-objective optimisation environment known as ModeFrontier. The modelling and simulations are performed in IPG CarMaker, with the post processing of the results taken care of by Sympathy for Data. Multiple optimization algorithms were tested to achieve the best optimisation routine. The EPAS parameters, namely the Basic Steering Torque, Active Return and Active Damping, act as the input to the optimization routine. The outputs of the model are the Objective Metrics, which provide a clear indication of the dynamic performance of a component. These metrics are optimized to _t the Steering DNA structure, which uniquely describes the attributes of a vehicle. The final optimised vehicle is manually tested at the track, to determine the real driving feel. / För att upprätthålla ett positivt momentum i såväl tekniska som logistiska utmaningar på dagens bilmarknad har stora biltillverkare börjat använda sig av virtuella simuleringsverktyg. Dessa verktyg möjliggör utveckling av diverse fordonsmodeller långt innan resurser investeras i en fysisk prototyp. Detta projekt fokuserar på utvecklingen av ett verktyg som potentiellt kan hjälpa att optimera dynamiska beteendeparametrar för ett fordon. Detta uppnås genom att skapa en optimeringsrutin för att ställa in de olika parametrarna för den elektroniska servostyrningen (EPAS). Denna process görs vanligtvis manuellt, genom test på provbana, på grund avsvårigheterna att korrelera subjektiva bedömningar (SA) med objektiva mätetal (OM). Att automatisera denna process kan bidra till att minska den övergripande forsknings- och utvecklingstiden genom att tillhandahålla en baslinje för EPAS-parametrarna som i efterhand kan finjusteras genom manuell justering på provbana. Verktyget är byggt genom att ansluta olika program i en optimeringsmiljö som kallas ModeFrontier. Modellering och simuleringar utförs i IPG CarMaker, med efterbehandling av resultaten i Sympathy for Data. Flera optimeringsalgoritmer testades för att uppnå bästa optimeringsrutinen. EPAS-parametrarna består av det grundläggande styrmomentet, aktiv retur och aktiv dämpning, och fungerar som invärden till optimeringsrutinen där utvärdera från modellen är objektiva mätetalen, vilket ger en tydlig indikation på den dynamiska prestandan hos en komponent. Dessa mätvärden optimeras för att passa Steering DNA-strukturen, som unikt beskriver egenskaperna hos ett fordon. Det slutliga optimerade fordonet testas manuellt på provbana för att bestämma den verkliga körkänslan.

The tyre is an essential part of a road vehicle. It is in the contact between road and tyre that the forces that create the possibility for the driver to control the vehicle are generated. Tyres, however, wear down, which leads to both unhealthy wear particles and disposal of old tyres, both of which are harmful to the environment. If one could learn more about what causes wear, it might be possible to reduce tyre wear, which would be beneficial from both an economic and an ecological point of view. The aim of this thesis work is to develop a tyre model that can simulate tyre wear and take temperature, pressure and vehicle settings into account. Based on tyre brush theory, a tyre wear model has been developed which includes a thermal model, a pressure model and a friction model. Simulations and analysis of different cases has been performed. From the results, one can conclude the following: the tyre temperature and inflation pressure change with the distance the vehicle travels at the beginning and later become steady; higher external temperature will decrease tyre wear rate since the inflation pressure increases with the external temperature and the sliding friction decreases; higher vehicle speed leads to a higher tyre wear rate; the tyre temperature increases with increasing vehicle speed; the amount of tyre wear increases linearly with the normal load on the tyre; the tyre wear increases with the slip ratio exponentially due to both the siding distance and the sliding friction increasing with the slip ratio; the tyre wear increases exponentially with the slip angle. The complete model can estimate the tyre wear with different vehicle settings and external factors. More experiments are needed in the future to validate the complete model. In addition, since the heat transfer coefficient is changeable with temperature, the thermal model can be improved by introducing dynamic heat transfer coefficients. The Savkoor friction model used in the report can also be improved by tuning its parameters using more experimental data.

To produce competitive vehicles, their comfort is one important issue to take into account during the development process. The aim of this Master Thesis is to develop an on-line comfort evaluation tool in order to improve research and education in the field of vehicle comfort at the division of Vehicle Dynamics at the Royal Institute of Technology. Based on ISO standards concerning comfort an on-line evaluation tool has been developed using DASYLab, which is a software that allows creation of acquisition, control, simulation and analysis tasks. The developed tool has been evaluated by performing measurements of a VOLVO V40 equipped with sensors. Different sorts of surfaces and driving conditions have been investigated, and from this investigation one can conclude that the comfort tool works properly.

Wheel-rail contact is an important aspect of railway, the forces transferred between the wheel and rail are the one that guide, brake, or accelerate the train, and that is why the understanding of the contact between wheel and rail is an interesting research topic. In this master thesis wheel-rail contact model named ANALYN is used to see the effect of the different geometrical input, like undeformed distance, relative longitudinal curvature, and relative lateral curvature calculation affect the contact patch estimation formed at the wheel-rail contact.  In the process, a geometrical contact search code is made to find the contact point between wheel and rail for certain lateral displacement, yaw angle, and roll angle of the wheelset. The codes used to calculate the three geometrical inputs are also prepared, with two methods are prepared for each input. The results that generated from combination of the geometrical contact search and geometrical input preparation are used as the input to ANALYN. The results showed that different geometrical input calculations do affect the shape of the contact patch, with the calculation of lateral curvature being the most important since it affects the shape of the contact patch greater than other geometrical inputs. It is also shown that taking yaw angle into account in the contact search will affect the shape of the contact patch.

The evolution of injection processes toward more fuel efficient and less polluting combustion systems tend to make them more prone to critical events such as Thermo-Acoustic Instabilities, Blow-Off and Flash-Back. Moreover, the addition of Di-Hydrogen as a secondary or as the main fuel is in discussion by aeronautical engines manufacturers. It drastically modifies the stability of the system and thus raise several interrogations concerning the multiplicity of its use. Being able to predict critical phenomena becomes a necessity in order to efficiently operate a system without having to pre-test every configuration and without sacrificing the safety of the user. Based on Deep Learning techniques and more specifically Speech Recognition, the following study presents the steps to develop a tool able to successfully detect and translate precursors of instability of an aeronautical grade swirled injector confined in a tubular combustion chamber. The promising results obtained lead to proposals for future transpositions to real-size systems. / Utvecklingen av injektionsprocesser mot mer bränsleeffektiva och mindre förorenande förbränningssystem, tenderar att göra dem mer benägna att utsättas för kritiska händelser som Thermo-Acoustic Instabilities, Blow-Off och Flash-Back. Dessutom diskuterar flygmotorkonstruktörer möjligheten att använda Dihydrogen som sekundärt eller som huvudbränsle. Det modifierar drastiskt systemets stabilitet och det väcker frågan hur man kan använda det effektivt. Att kunna förutsäga kritiska fenomen blir en nödvändighet för att använda ett system utan att behöva att på förhand testa varje konfiguration och utan att reducera användarens säkerhet. Baserat på Deep-Learning-tekniker och Speech-Recognition-tekniker, presenterar följande studie stegen för att utveckla ett verktyg som kan upptäcka och översätta föregångare till instabilitet hos en swirled flygmotorerinsprutningspump som är innesluten i en förbränningskammare. De lovande resultaten leder till idéer om hur man kan anpassa det här verktyg till ett system i verklig storlek.