This study aims to perform a feasibility study on the DTU 10MW-RWT wind turbine blades constructed in the fossil-free high-strength steel 1300 MPa from SSAB. The acceptance criteria, on which the study is based, are taken from the DTU composite wind turbine model. A maximum weight of 41 000kg and a maximum tip displacement of 12.5 m are chosen. By fulfilling the acceptance criteria, the results of this study could contribute to a more sustainable future by decreasing the carbon dioxide emissions of wind turbine blades and improving their  recycling options. To perform weight optimization the Finite Element Analyses software Abaqus and the optimization software Tosca Structure are used.  The study is conducted based on Design for Six Sigma (DFSS) up until the design concept SG2. The study results in a preliminary design of the wind turbine blade constructed in SSAB Strenx 1300 and proofs that Tosca is a suitable software for performing weight optimization. The results show that it would be feasible to replace the wind turbine blades with SSAB Strenx 1300 MPa, but it will result in a weight increase for the current design. For further studies, it is recommended to consult with the stakeholders on how much weight increase of the blade is acceptable and study on how to modify the design of the steel wind turbine blade.

Indiana University-Purdue University Indianapolis (IUPUI) / Lately numerous studies have been performed to design composite monocoques with high strength and low weight for various student level racing contests. The objective of this paper is to develop an insightful methodology to design and de veloped a light-weight composite monocoque. The monocoque is designed to pass the mandatory static load tests laid down by the International Automobile Feder ation (FIA)Formula 3. These Formula 3 tests are considered the baseline of the desired structural integrity of the composite monocoque. The presented design tech nique emphasises on a monocoque developed for Sports Car Club of America (SCCA) races. The three standard load tests performed on the monocoque are Survival Cell Side test, Fuel Tank test and Side Intrusion test. A sandwich layup of bi-directional woven carbon/epoxy prepreg and aluminium honeycomb is optimized for minimum weight while predicting the unknown properties of layup and ensuring the mono coque doesnt experience failure. The approach intends to achieve minimum weight with high torsional rigidity and is capable of being used for the design and analysis of any kind of formula type composite monocoque.

Indiana University-Purdue University Indianapolis (IUPUI) / In a multifidelity structural design process, depending on the required analysis, different levels of structural models are needed. Within the aerospace design, analysis and optimization community, there is an increasing demand for automatic generation of parametric feature tree (build recipe) attributed multidisciplinary models. Currently, this is mainly done by creating separate models for different disciplines such as mid-surface model for aeroelasticity, outer-mold line for aerodynamics and CFD, and built-up element model for structural analysis. Since all of these models are built independently, any changes in design parameters require updates on all the models which is inefficient, time-consuming and prone to deficiencies. In this research, Engineering Sketch Pad (ESP) is used to create attribution and maintain consistency between structural models with different fidelity levels. It provides the user with the ability to interact with a configuration by building and/or modifying the design parameters and feature tree that define the configuration. ESP is based an open-source constructive solid modeler, named OpenCSM, which is built upon the OpenCASCADE geometry kernel and the EGADS geometry generation system. The use of OpenCSM as part of the AFRL’s CAPS project on Computational Aircraft Prototype Syntheses for automatic commercial and fighter jet models is demonstrated. The rapid generation of parametric aircraft structural models proposed and developed in this work will benefit the aerospace industry with coming up with efficient, fast and robust multidisciplinary design standardization of aircraft structures. Metallic aircraft wings are usually not optimized to their fullest potential due to shortage of development time. With roughly \$1000 worth of potential fuel savings per pound of weight reduction over the operational life of an aircraft, airlines are trying to minimize the weight of aircraft structures. A stiffness based strategy is used to map the nodal data of the lower-order fidelity structural models onto the higher-order ones. A simple multi-fidelity analysis process for a parametric wing is used to demonstrate the advantage of the approach. The loads on the wing are applied from a stick model as is done in the industry. C program is created to connect the parametric design software ESP, analysis software Nastran, load file and design configuration file in CSV format. This problem gets compounded when it comes to optimization of composite wings. In this study, a multi-level optimization strategy to optimize the weight of a composite transport aircraft wing is proposed. The part is assumed to initially have some arbitrary number of composite super plies. Super plies are a concept consisting of a set of plies all arranged in the same direction. The thickness and orientation angles of the super plies are optimized. Then, each ply undergoes topometry optimization to obtain the areas of each super ply taking the least load so that it could be cut and removed. Each of the super plies are then optimized for the thickness and orientation angles of the sub plies. The work presented on this paper is part of a project done for Air Force Research Laboratory (AFRL) connecting the parametric geometry modeler (ESP) with the finite element solver (Nastran).

Structural Optimization techniques are widely used in product development process in ‘modern industry’ to generate optimal designs with only sufficient material to serve the purpose of the component. In conventional design problems, the design process usually generates overdesigned components with excess material and weight. This will in turn increase the life time cost of machines, both in terms material wastage and expense of usage. The thesis “Design of a weight optimized casted ADI component using topology and shape optimization” deals with redesigning a component from a welded steel plate structure into a castable design for reduced manufacturing cost and weight reduction. The component “Drill Steel Support” mounted in front of the drilling boom of a Face Drilling Machine is redesigned during this work. The main objective of the thesis is to provide an alternative design with lower weight that can be mounted on the existing machine layout without any changes in the mounting interfaces. This thesis report covers in detail procedure followed for attaining the weight reduction of the “Drill Steel Support” and presents the results and methodology which is based on both topology and shape optimization. / Strukturoptimering används ofta i produktutvecklingsprocessen i modern industri för att ta fram optimala konstruktioner med minsta möjliga materialåtgång för komponenten. Konventionella konstruktionsmetoder genererar vanligtvis överdimensionerade komponenter med överflödigt material och vikt. Detta ökar i sin tur livstidskostnaderna för maskiner både i termer av materialavfall och användning. Avhandlingen "Konstruktion av viktoptimerad gjuten ADI-komponent" behandlar omkonstruktionen av en komponent från en svetsad stålplåtstruktur till en gjutbar konstruktion med minskad tillverkningskostnad och vikt. Komponenten “Borrstöd” monterad i framkant av bommen på en ortdrivningsmaskin är omkonstruerad under detta arbete. Huvudsyftet med avhandlingen är ta fram en alternativ konstruktion med lägre vikt och som kan monteras på befintlig maskinlayout utan någon ändring i monteringsgränssnittet. Denna avhandling innehåller en detaljerad beskrivning av förfarandet för att uppnå viktminskningen av "borrstödet" och presenterar resultaten samt metodiken som baseras på både topologi- och parameter- optimering.

I och med en ökande konkurrens och tekniska framsteg har flygbranschen tvingats ta till nya metoder för att utveckla komponenter. I flygbranschen är viktoptimering en viktig faktor och på senare tid har man sett stora möjligheter med att genomföra detta med hjälp av topologioptimering och additiv tillverkning. På Saab finns det ett intresse av att undersöka hur topologioptimering kan användas för att om möjligt förenkla och förbättra den utvecklingsprocess man har i dag och göra de produkterna man tillverkar ännu bättre. Speciellt vill man titta på hur topologioptimeringsmodulen i det befintliga CAD systemet Siemens NX fungerar för att se hur konstruktörer skulle kunna använda sig av verktyget för att minska vikten på komponenterna. Syftet med denna studie är att undersöka hur topologioptimering kan genomföras i Siemens NX för att se hur det kan användas i utvecklingsarbetet på Saab samt för att se vilka möjligheter/utmaningar verktyget för med sig. Arbetet är baserat på en litteraturstudie, en intervjustudie, en workshop och undersökningar av Siemens NX topologioptimeringsmodul. Resultatet från intervjuerna visade att man på Saab ser en vinst i att använda sig av topologioptimering på flera ställen i utvecklingsprocessen. Undersökningen av Siemens topologioptimeringsmodul visar att verktyget kan användas, framförallt under en av de tidpunkterna i processen som föreslagits under intervjuerna, för att ta fram en kvalificerad första gissning på en konstruktion. Vinsten med att använda topologioptimering har visat sig vara att antalet iterationer mellan konstruktör och strukturanalytiker kan minska, vilket kan leda till en tidseffektiviserad utvecklingsprocess. Det har framkommit under intervju med en strukturanalytiker att färdiga komponenter, där topologioptimering använts, tenderar att vara bättre uppbyggda och ha lättare att klara av de ställda kraven. Arbetet har också visat att det finns utmaningar med att använda Siemens topologioptimeringsmodul på Saab. Ett av de stora problemen som framkommit under arbetet är att det är svårt att ta fram exakta lastfall på Saabs komponenter vilket krävs för att topologioptimera i Siemens NX. Ytterligare en försvårande faktor är att Saabs produkter i många fall har en låst förformskonstruktion med förutbestämda designparametrar, som dimensioner och funktioner. Detta medför att det i vissa fall varit svårt att få fram relevanta resultat. Resultaten från undersökning av Siemens topologioptimering har visat sig ge bäst resultat då den förformskonstruktion som optimeras har en stor designfrihet. / As a consequence of great technical progress in today's society and the increasing competition industries in between, the aviation industry has been forced to implement new methods in their product development to stay competitive. Topology optimization together with additive manufacturing is one of them and is used to optimize the weight of a component. Optimization in weight is a crucial factor in the aviation industry and topology optimization is recently shown to be a useful method. At Saab there is an interest in evaluating topology optimization and its capability to both improve and simplify today's development process to make even better products in the end. In particular, they want to look at how the topology optimization module in the existing CAD system Siemens NX works to explore the opportunities for the designersto reduce the weights of the components. This study aims to examine the use of topology optimization in Siemens NX to explore if it is a useful method to implement in the development process at Saab. The purpose is also to see what advantages and what challenges it brings. The work is based on a literature review, an interview study, a workshop and an investigation of the topology optimization module in Siemens NX.  Results from the interviews showed that Saab can benefit from the usage of topology optimization in several parts of the development process. Siemens NX topology optimization module, specifically, was found to fit in one of the suggested places, where it can be used to create a first qualified iteration. One of the advantages topology optimization can bring is fewer design iterations between designers and analysts which can help reduce the development time and improve the process. Furthermore one of the interviewed structural analysts claims that parts, where topology optimization tools has been used, has been found to be better constructed and has easier to pass through the validation process. The study has also revealed some difficulties with the usage of Siemens NX topology optimization module at Saab where the biggest question is whether relevant load cases exists or not. Topology optimization in Siemens NX requires definitive load cases which has been hard or even impossible to find in many of Saab´s products. Another difficulty with the usage of Siemens Topology optimization on Saab´s product is the limited freedom in the design space. The respondents mean that most of the constructed parts has a lot of predetermined parameters and in the topology optimization module this fact has sometimes made it difficult to produce relevant results.

Wind turbines have been utilized for centuries to harness energy from the wind. Commercial wind turbine blades are typically made from composite materials, which are difficult to recycle, leading to blades ending up in landfills at the end of their lifecycle. Additionally, these materials contribute to microplastic pollution. In response to growing environmental concerns, there has been an increased focus on addressing such issues. The Swedish company SeaTwirl AB develops offshore vertical-axis wind turbines (VAWT), and this study focuses on optimizing the weight of a blade from a new 10-15 MW VAWT concept using steel as the material. Steel has long been recyclable, making it an interesting material for wind turbine blades. The specific steel used in this study is the ultra-high-strength steel "Strenx 1300" from SSAB, which is not only extremely durable but is also expected to be fossil-free by 2026, by implementation of the manufacturing technology HYBRIT. The study found that a single blade made from Strenx 1300, when designed and optimized for 35 years of operational use, would weigh approximately 193.4 tonnes and would require 6016.8 meters of welds with a fatigue class of FAT 125. A rough estimation of the weight of a fiberglass VAWT of the same size resulted in approximately 300 tonnes. Therefore, this study concludes that it may be feasible to construct a commercially competitive VAWT blade using environmentally friendly, fossil-free steel. This approach would make wind energy a more sustainable energy source without the problems of recyclability and microplastic pollution. / Vindkraftverk har använts i århundraden för att utvinna energi från vinden. Kommersiella vindkraftverksblad tillverkas vanligtvis av kompositmaterial, vilket är svårt att återvinna och leder till att bladen hamnar på soptippar vid slutet av deras livscykel. Dessutom bidrar dessa material till mikroplastföroreningar. Som svar påväxande miljöproblem har det därför blivit ett ökat fokus på denna typ av frågor. Det svenska företaget SeaTwirl AB utvecklar vertikalaxliga vindkraftverk (VAWT) för offshore-användning, och denna studie fokuserar på att optimera vikten av ett blad från ett nytt 10-15 MW VAWT-koncept med stål som material. Stål har länge varit återvinningsbart, vilket gör det till ett intressant material för vindkraftverksblad. Det specifika stål som används i denna studie är det höghållfasta stålet "Strenx1300" från SSAB, som inte bara är extremt hållbart, men också förväntas bli fossilfritttill 2026, tack vare implementeringen av tillverkningsteknologin HYBRIT. Studien visade att ett enskilt blad tillverkat av Strenx 1300, när det är utformat och optimerat för 35 års driftstid, skulle väga cirka 193,4 ton och kräva 6016,8 meter svets med en utmattningsklass FAT 125. En grov uppskattning av vikten av en VAWT av samma storlek i glasfiber resulterade i cirka 300 ton. Därför drar denna studie slutsatsen att det kan vara möjligt att konstruera ett kommersiellt konkurrenskraftigt VAWT-blad med miljövänligt, fossilfritt stål. Detta tillvägagångssätt skulle göra vindenergi till en mer hållbar energikälla utan problemen associerade med återvinning och mikroplaster.