Topology optimization is a method providing new direction in designing of a technical objects. The aim of topology optimization is to find optimal distribution of material in design space. This diploma thesis is focused on optimization of aircraft wing rib num.6 of the airplane EV-55 using a software HW/Optistruct 7.0 implemented in a software package HyperWorks 7.0. The optimization of the rib was calculated under four different load cases. Resulting shapes of the rib were then tested by strenght calculations in software ANSYS 10.0. Finally, the obtained data of weights of optimized ribs were compared with the weight of the original rib.

<p>Den här rapporten handlar om det examensarbete som utförts mot Volvo 3P genom forskningsprojektet Viktor. Viktor är ett projekt som ska visa möjligheten med virtuell produktframtagning av gjutna komponenter. Volvo 3P är ett företag som utvecklar lastbilar. Uppgiften har varit att visa möjligheten att använda topologioptimering som ett verktyg i konstruktionsfasen. Detta har gjorts med hjälp av ett case som erhållits från Volvo 3P. Ett nytt koncept för en av deras lastbilsnav har tagits fram. Konceptet visar på högre styvhet och en lägre spänningsnivå än dagens originalnav. Konceptet hade förmodligen aldrig uppkommit om det inte hade varit för topologioptimeringen. Rapporten behandlar de steg som utförs vid en topologioptimering med programvaran Altair Hypermesh Optistruct. För att verifiera de resultat som erhållits från topologioptimeringen har koncepten analyserats i Abaqus. Rapporten tar även upp begränsningar och svårigheter som användaren kan komma att stöta på under arbetets gång.</p> / <p>This report documents the final project which has been performed in collaboration with Volvo 3P through the science project named Viktor. Viktor is a project which will show the opportunities with virtual product development of cast iron products. Volvo 3P is a company which among other things develops trucks. The task has been to show opportunities with topology optimization as a tool in the construction phase. This has been done with help from a case that has been received from Volvo 3P. A new concept for one of their hubs has been developed. The concept shows greater stiffness and a lower stresses compared to the original hub. The concept would probably not have been developed without using topology optimization. This report concerns the multiple steps which are used to perform optimization with the computer program Altair Hypermesh Optistruct. To verify the results which has been received from the topology optimization Abaqus has been used as a FE-tool. The report also contains the limits and difficulties which can occur during the process</p>

Loss of bone in the mandible as a result from for example resection of bone tumors or trauma, can in more complex cases be reconstructed using a reconstruction plate to provide stability between the remaining mandible stumps. Different studies on reconstruction plates present a fracture rate of 2.8-9.8 %. The rate of plate fracture and plate loosening increases the need to improve the design of the reconstruction plate. A useful tool to find new designs for structures is topology optimization. Topology optimization is a mathematical based method where it is possible to define an optimization problem for a specific load case. Based on the defined problem, the solver calculates the most appropriate design to reach the final goal. The aim of this work is to investigate, describe, and discuss how new designs for reconstruction plates used for bridging large mandibular defects can be achieved by using topology optimization as a tool.   Two software programs handling topology optimization from Altair Engineering were used: SimLab 14.0 and HyperMesh 14.0. Both of them uses the solver OptiStruct to solve the defined topology optimization problem. The topology optimization problem was defined to minimize the compliance of the structure with an upper limit of the allowed volume fraction used for the new design. Three different clenching tasks were examined: right unilateral clench, clenching in the intercuspal position, and incisal clench. All three load cases resulted in different designs, the designs were also affected by the initial amount of screws used, and by the defined value on the allowed thickness of the created parts in the new design. The results gave an initial understanding of topology optimization, and indicated the possibilities a design process with topology optimization has to achieve new designs for reconstruction plates used for large mandibular fractures.

Due to the competitive nature of airline industry and the desire to minimise aircraft weight, there is a continual drive to develop lightweight, reliable and more comfortable seating solutions, in particular, a new generation slim economy seat. The key design challenge is to maximise the “living space” for the passenger, with strict adherence to the ‘Crash Safety Regulations’. Cranfield University is addressing the needs of airliners, seat manufactures and safety regulating bodies by designing a completely novel seat structure coined as “Sleep Seat”. A generous angle of recline (40 degree), movement of “Seat Pan” along the gradient, fixed outer shell of the backrest, and a unique single “Forward Beam” design distinguishes “Sleep Seat” form current generation seats. It is an ultra-lightweight design weighing 8kg (typical seat weight is 11kg). It has to sustain the static (CS 25.561) and dynamic (CS25.562) “Emergency landing” loads as specified by “Certification Specifications (CS). Apart from maintaining structural integrity; a seat-structure must not deform, which would impede evacuation, should absorb energy so that the loads transferred to Occupants are within human tolerance limits and should always maintain survivable space around the Occupant. All these parameters, which increase a life-expectancy in a ‘survivable’ crash, can be estimated using either experimental testing or virtual simulation tools such as “Finite Element Analysis (FEA). Design of the “Sleep Seat” is still in its conceptual phase and therefore experimental testing for all the design iterations involved is unrealistic, given a measure of the costs and timescales involved. Therefore focus of research is to develop practical and robust FE methodologies to assess static and dynamic performances of a seat-structure so as to compare different design concepts based on their strength, seat interface loads (a limit defined by strength of aircraft-floor), maximum deformations and cross-sectional forces ... [cont.].

Den här rapporten handlar om det examensarbete som utförts mot Volvo 3P genom forskningsprojektet Viktor. Viktor är ett projekt som ska visa möjligheten med virtuell produktframtagning av gjutna komponenter. Volvo 3P är ett företag som utvecklar lastbilar. Uppgiften har varit att visa möjligheten att använda topologioptimering som ett verktyg i konstruktionsfasen. Detta har gjorts med hjälp av ett case som erhållits från Volvo 3P. Ett nytt koncept för en av deras lastbilsnav har tagits fram. Konceptet visar på högre styvhet och en lägre spänningsnivå än dagens originalnav. Konceptet hade förmodligen aldrig uppkommit om det inte hade varit för topologioptimeringen. Rapporten behandlar de steg som utförs vid en topologioptimering med programvaran Altair Hypermesh Optistruct. För att verifiera de resultat som erhållits från topologioptimeringen har koncepten analyserats i Abaqus. Rapporten tar även upp begränsningar och svårigheter som användaren kan komma att stöta på under arbetets gång. / This report documents the final project which has been performed in collaboration with Volvo 3P through the science project named Viktor. Viktor is a project which will show the opportunities with virtual product development of cast iron products. Volvo 3P is a company which among other things develops trucks. The task has been to show opportunities with topology optimization as a tool in the construction phase. This has been done with help from a case that has been received from Volvo 3P. A new concept for one of their hubs has been developed. The concept shows greater stiffness and a lower stresses compared to the original hub. The concept would probably not have been developed without using topology optimization. This report concerns the multiple steps which are used to perform optimization with the computer program Altair Hypermesh Optistruct. To verify the results which has been received from the topology optimization Abaqus has been used as a FE-tool. The report also contains the limits and difficulties which can occur during the process

Due to the competitive nature of airline industry and the desire to minimise aircraft weight, there is a continual drive to develop lightweight, reliable and more comfortable seating solutions, in particular, a new generation slim economy seat. The key design challenge is to maximise the “living space” for the passenger, with strict adherence to the ‘Crash Safety Regulations’. Cranfield University is addressing the needs of airliners, seat manufactures and safety regulating bodies by designing a completely novel seat structure coined as “Sleep Seat”. A generous angle of recline (40 degree), movement of “Seat Pan” along the gradient, fixed outer shell of the backrest, and a unique single “Forward Beam” design distinguishes “Sleep Seat” form current generation seats. It is an ultra-lightweight design weighing 8kg (typical seat weight is 11kg). It has to sustain the static (CS 25.561) and dynamic (CS25.562) “Emergency landing” loads as specified by “Certification Specifications (CS). Apart from maintaining structural integrity; a seat-structure must not deform, which would impede evacuation, should absorb energy so that the loads transferred to Occupants are within human tolerance limits and should always maintain survivable space around the Occupant. All these parameters, which increase a life-expectancy in a ‘survivable’ crash, can be estimated using either experimental testing or virtual simulation tools such as “Finite Element Analysis (FEA). Design of the “Sleep Seat” is still in its conceptual phase and therefore experimental testing for all the design iterations involved is unrealistic, given a measure of the costs and timescales involved. Therefore focus of research is to develop practical and robust FE methodologies to assess static and dynamic performances of a seat-structure so as to compare different design concepts based on their strength, seat interface loads (a limit defined by strength of aircraft-floor), maximum deformations and cross-sectional forces ... [cont.].

Ride and handling are important areas for safety and improved vehicle control during driving. To meet the demands on ride and handling a number of measures can be taken. This master thesis work has focused on the early design phase. At the early phases of design, the level of details is low and the design freedom is big. By introducing a tool to support the early vehicle body design, the potential of finding more efficient structures increases. In this study, topology optimization of a vehicle front structure has been performed using OptiStruct by Altair Engineering. The objective has been to find the optimal topology of beams and rods to achieve high stiffness of the front structure for improved ride and handling. Based on topology optimization a proposal for a beam layout in the front structure area has been identified. A vital part of the project has been to describe how to use topology optimization as a tool in the design process. During the project different approaches has been studied to come from a large design space to a low weight architecture based on a beam-like structure. The different approaches will be described and our experience and recommendations will be presented. Also the general result of a topology-optimized architecture for vehicle body stiffness will be presented.

Due to a need of more compact bogies, the brake discs can be mounted on the railway wheels, bolted through the wheel web. Thus, the wheels are drilled and have multiple areas of contact with the brake discs. To establish maintenance procedures that will be applied to the  wheels,  SNCF  used  the  feedback  from  experience  (as  with  the  train  AGC)  which  gives  perfect  performance  in  terms  of  safety.  However,  to  optimize  the  maintenance  process, numerical  simulations  may  be  preferred  since  they  are  less  conservative.  This  report  describes  the  numerical  simulations,  based  on  the  finite  element  method,  that  were conducted to determine if the Régiolis wheel complies with the standard EN 13979-­‐1 from a mechanical  fatigue  point  of  view.  In  addition,  it  provides  additional  insights  regarding  the  loads and damage suffered by the wheel, which are not taken into account in the standard: the  damage  induced  by  disc  braking  and  the  fretting  that  may  occur  at  the  contact  interfaces. This study has been used as a decision support for the first inspection intervals of the Régiolis wheels.

In the past decades of years, huge amounts of people chose to move to big cities for better education and medical service, which also makes many cities are very crowded and noisy. Moreover, the house rent in city center is some kind too expensive for many people, especially for the youth. In this sense, more people are willing to live in suburb instead of city center. Due to the larger distance between home and office, people’s requirement for a faster public transportation method is enormous. Elon Musk first publicly mentioned the concept of Hyperloop in 2012[1], which is a sealed tube or system of tubes with nearly vacuum condition through which a pod can transport people or objects at super high velocity. With the linear induction motor and magnetic levitation technology, the drag force on the pod can be reduced tremendously, thus increasing the peak velocity to 1200 km/h. To gather more ideas for this concept, SpaceX holds the Hyperloop Pod Competition where worldwide teams will design their own Hyperloop pod to demonstrate their technical feasibility of new ideas [2]. A Hyperloop system is currently in development by the Integrated Transport Research Lab (ITRL) at KTH Royal Institute of Technology to participate in the upcoming Hyperloop Pod Competition. KTH Hyperloop group has some primary design of chassis and shell. However, they have no idea how good of their current design is. Furthermore, since the velocity is the only criteria for this competition, they also want to reduce the mass as much as possible. In this sense, some finite element analysis and optimization analysis are necessary. The objective of this master’s thesis is to analyze the current shell and chassis design to assess the quality of the attachments and integrity of the design and to reduce the total mass while keeping the stiffness within the safety range. The used tools are HyperMesh, Optistruct and HyperView which are parts of the software HyperWorks from Altair. / Ett Hyperloop-system utvecklas för närvarande av Integrated Transport Research Lab (ITRL) vid KTH Royal Institute of Technology för att delta i den kommande Hyperloop Pod-tävlingen. Hyperloop-gruppen vid KTH har utvecklat en primärkonstruktion av chassi och skal. De har dock ingen aning om hur bra deras nuvarande design är. Eftersom hastigheten är de enda kriterierna för denna tävling, vill de också minska massan så mycket som möjligt. I detta avseende är det nödvändigt med finita element- och optimeringsanalyser. Syftet med denna masteruppsats är att analysera den aktuella skal- och chassikonstruktionen för att utvärdera kvaliteten på dess fästen och integriteten hos designen, samt att minska den totala massan samtidigt som styvheten uppfyller specificerat krav. De använda verktygen är HyperMesh, Optistruct och HyperView som är delar av programvaran HyperWorks från Altair.