Experimental characterization of the mechanical properties in a thin injection moulded Low-Density Polyethylene (LDPE) plate is per- formed in this work. Anisotropy in LDPE at different material orientations is measured from the Digital Image Correlation (DIC) observation of the specimens during uniaxial tensile test. From the test response and observation from DIC, the studied material is found to be significantly anisotropic. Finite Element simulation (FE-simulation) of in-plane anisotropy of material is carried in AbaqusTM R2020 using available models like Hill48 and Barlat2004. When necessary the simulation plastic potentials for these models are optimized against experimental yield stress ratio (R) and anisotropic ratio (r). To express the nonlinear mechanical behavior, a suitable hardening extrapolation model, namely Swift/Hockett-Sherby is selected from several extrapolation models based on experimental data. To validate the experimental methods, simulation methods and material characterization process, finite element simulation results such as force displacement, strain distribution and different anisotropic related properties are compared with the experimental data. Finally, advantages and disadvantages of different simulation models are discussed.

Stockholms stads kulturskoleverksamhet behöver fler och bättre anpassade lokaler snabbt. Förslaget “Kulturskolan Tältet” berättar med sin gestalt om dess ambition att “växa och beskäras” samt agera som sambandscentral för uppsökande kulturskoleverksamhet. Alla valda byggmaterial är återvinningsbara och en stor del av byggnaden kan prefabriceras av tidigare återvunnet material och i sin tur sammansättas på mindre än ett halvår. Byggprincipen är mycket billig och enkel att anpassa, flytta och utöka; Ett femtiotal ombyggda containrar är importerade till platsen, ställda på en betongplatta och kapslade av en kanalplastfasad samt ett generöst tälttak buret av vertikala limträelement. Byggnaden innehåller en stor halvklimatiserad omprogrammerbar arbetsyta anpassad för inlastning och ombyggnation av containrar som i nästa steg flyttas till Stockholms skolgårdar fyllda med kulturverksamhet. Förslaget innehåller även den framtida nya tunnelbaneuppgången för den stundande orangea linjen och skapar ett tydlig rum mellan uppgången och skolan där mässbesökare, pendlare och kulturskoleelever har samma rätt till platsen och bildar en ny stark knytpunkt mellan förstad och stad. / Stockholm's Culture school need more and better adapted spaces quickly. The proposal "Culture school the Tent" speeks in its gestalt of its ambition to "grow and be pruned" and also act as liaison for outreach cultural school activities. All chosen materials are recyclable and a large part of the building can be prefabricated of previously recycled materials and in turn be assembled in less than six months. The construction principle is very cheap and easy to adapt, move and expand; Fifty rebuilt containers are imported to the site, set on a concrete slab and enclosed by a corrugated plastic facade, as well as a generous tent roofing carried by vertical glued wood elements. The building contains a large half acclimatised reprogrammable workspace suited for loading and refurbishment of containers and in the next step exported to Stockholms school yards filled with cultural activities. The proposal also includes new subway entrance for the coming "orange line" and creates a distinct place between the entrances of the subway and the school where fair visitors, commuters and culture school students have the same right to the site and forms a new strong connection point between suburban and urban.

With the rapid increase in utilization of the cheap and user friendly Fused Filament Fabrication, FFF 3D printer, a deeper knowledge about the technique is needful. The frame restricting the 3D printers for prototyping purposes is fading and a new phase of endless application possibilities is emerging. To bridge the gap in possible applications from prototypes to real products it is key to know and improve the factors affecting durability. With over a hundred settings and parameters to tweak the FFF 3D printing process there are a lot of opportunities, opportunities to optimize for durability.The tensile properties of some of the most used FFF 3D printing materials together with a few nylon based materials are examined, which are popular in engineering applications. The materials tested are ranging from rigid to flexible, rubber like materials. The most common failure scenario of a FFF 3D printed product is layer bonding failure. The factors affecting layer bonding performance are studied.The measurements are carried out using tensile testing equipment at Blekinge Institute of Technology. All tested specimens are manufactured at Creative Tools AB Halmstad with the FFF 3D printers Flashforge Dreamer and Makerbot Replicator 2X.The tensile strength of 3D printed PLA is found to be 51 MPa. PET has a tensile strength of 40 MPa and ABS 34 MPa. Stress-strain behavior of the materials shows that ABS is slightly softer than PLA and PET are slightly softer than ABS. PLA being the hardest material in the test. ISO 527-2 tensile testing standard is used but the tests diverge from the standard in several ways. The measurement data presented in this study can be very useful to guide the design engineer to choose the most durable plastic for the unique application.Five basic 3D printing settings are evaluated for layer bonding performance, by measuring the load capacity of a PLA specimen loaded transversally relative to the layers. Four of the settings show to possibly affect the layer bond’s load capacity by 50 % or more individually.The results of this study are presented in graphs, diagrams and pictures. These may help the 3D printer user to tweak basic settings to increase layer bonding performance and ultimately the durability of the product significantly.

Today, structural adhesives are found extensively in load-bearing engineering applications, as their use can be advantageous compared to other fastening methods. However, the characteristics of adhesives are far more complex, making it challenging to predict their behavior in different service conditions. In addition, environmental factors like temperature and water can affect the performance of an adhesive bond both physically and chemically. This work was initiated by MuoviTech AB and aims to evaluate the performance of structural methyl methacrylate adhesives cured in different environmental conditions. The study began with a literature review to find relevant research and literature about structural adhesives, their material characteristics, and the effects of temperature and water on the performance of adhesive bonds. A market survey was conducted to find products suitable for the experiment, and Araldite 2050, Araldite 2051, Permabond TA4200, 3M DP8810NS, LoctiteHY 4070, and Acralock SA 10-05 were selected together with MuoviTech AB. The laboratory work began with sample preparation in terms of abrasion and cleaning of the surface. The adhesives were applied to the samples, and single-lap joints were prepared and cured in room temperature and normal humidity, as well at 5 °C and underwater, for 24 hours. Single-lap shear tests were performed according to American standard ASTM D3163. Lastly, differential scanning calorimetry (DSC) was utilized for the thermal analysis of the samples cured at 5 °C and underwater. The results showed that neither of the adhesives performed in the range specified in the manufacturers’ technical data sheets (TDS). Lower failure strength and elongation was observed for the samples cured at 5 °C and underwater, compared to the samples cured in the optimal condition. However, Loctite HY 4070 showed an increase in failure strength. The DSC analysis revealed various degrees of post-curing. Further investigation with prolonged curing time and more environmental conditions are recommended. New tests for Loctite HY 4070 is also recommended to confirm the results. / Idag finns strukturella lim i stor utsträckning i bärande tekniska applikationer, eftersom deras användning kan vara fördelaktig jämfört med andra fästmetoder. Limmens egenskaper är dock mycket mer komplexa, vilket gör det svårt att förutsäga deras beteende under olika serviceförhållanden. Dessutom kan miljöfaktorer som temperatur och vatten påverka en limbindnings prestanda både fysiskt och kemiskt. Detta arbete initierades av MuoviTech AB och syftar till att utvärdera prestanda för strukturella metylmetakrylatlim härdade under olika miljöförhållanden. Studien inleddes med en litteraturöversikt för att hitta relevant forskning och litteratur om strukturella lim, deras materialegenskaper och effekterna av temperatur och vatten på limförbandens prestanda. En marknadsundersökning genomfördes för att hitta produkter som var lämpliga för experimentet, och Araldite 2050, Araldite 2051, Permabond TA4200, 3MDP8810NS, Loctite HY 4070 och Acralock SA 10-05 valdes tillsammans med MuoviTech AB. Arbetet i laboratoriet inleddes med provförberedelse genom slipning och rengöring av provens yta. Lim applicerades på proverna och förband med enkla överlapp (single-lap) bereddes och härdades i rumstemperatur och normal fuktighet, liksom vid 5 ° C och under vatten, under 24 timmar. Skjuvtester utfördes enligt den amerikanska standarden ASTM D3163. Slutligen användes differentiell svepkalorimetri (DSC) för termisk analys av proverna som härdades vid 5 ° C och under vatten. Resultaten visade att inget av limmen presterade i enlighet med det som beskrevs i tillverkarnas tekniska datablad (TDS). Däremot så observerades en lägre brottstyrka och töjning för proverna som härdades vid 5 ° C och under vatten, jämfört med de prover som härdades i det optimala tillståndet. Loctite HY 4070 visade emellertid en ökning av brottstyrka. DSC-analysen gav indikation på att olika grader av efterhärdning. Ytterligare undersökningar med längre härdningstid och med flera miljöförhållanden rekommenderas. Nya tester för Loctite HY 4070 rekommenderas också för att bekräfta resultaten.

Maintenance and rehabilitation of existing masonry and reinforced concrete structures are of great importance in the field of civil engineering. Due to deterioration and severe environment, numerous structures fail to meet functional or safety requirements, and as a result, they should be strengthened. Several methods have been utilized to repair the structures, including steel plate bonding, cable post-tensioning, and section enlargement. However, these methods bring disadvantages, such as significant added dead load and high labour cost. Therefore, externally bonding with composite materials has attracted considerable attention recently. Externally bonded fibre-reinforced polymer (FRP) sheets have been widely used to strengthen reinforced concrete and masonry structures. FRP has been a common method to provide a higher service life for structures for several decades. However, strengthening structural members with FRP introduces certain drawbacks, such as their poor performance in fire scenarios caused by the rapid softening of the polymer-based resin. An alternative strengthening system known as a fabric-reinforced cementitious matrix (FRCM) has been developed to address this issue by replacing resin-based material with an inorganic cementitious-based matrix. Nonetheless, the performance of FRCM at high temperatures has not been investigated sufficiently so far. Hence, this research focused on the mechanical behaviour of FRCM at high temperatures. This experimental research investigates the tensile performance of carbon FRCM at high temperatures. First, the temperature distribution within the specimens during heating was studied using nine specimens with one, two, or three layers to reveal the required time for the inner fabric to reach a steady temperature. Then, the tension and stiffness degradation of FRCM coupons were studied at different temperatures. A total of 84 FRCM coupons were fabricated and tested in tension; 60 of the tests were conducted at steady-state conditions in which temperature was held constant and load increased, and 24 specimens were carried out in transient-state tests, in which load was constant, and temperature grew. In order to provide a more comprehensive knowledge concerning the FRCM composite, some key variables were included in this research. These parameters are the number of layers (1, 2, 3) leading to different thicknesses (20, 30, 40 mm), the orientation of the fabric layer (unidirectional and bidirectional), target temperature (ambient, 100, 200, 300, 400°C), and heating condition (steady-state, transient state). These tests aimed to reveal the primary mechanical characteristics such as ultimate strength and cracked elastic modulus at different temperatures and compare them with control specimens tested at room temperature. With the increase in the number of fabric grids from one to two and three, the stress at failure decreased by about 11 and 18%, respectively. With regards to cracked elastic modulus two and three-layered specimens showed 18 and 20% reduction in value. It is also noteworthy to mention that overall load capacity of specimens rose with the increase in number of layers; however, due to the more significant increase in area, the stress was reduced. The same decreases in the cracked elastic modulus and ultimate strength were observed as the target temperature increased. Increasing the temperature to 400°C led to a decrease in ultimate strength and cracked elastic modulus of approximately 60 to 70%. Furthermore, the bidirectional specimens showed a better behaviour than unidirectional specimens in terms of ultimate strength; however, their cracked elastic moduli were almost the same. With regards to the transient-state tests, as the material became thicker, the failure temperature increased considerably. For instance, a 20-mm specimen failed at 467°C with a 20% sustained load, while a 30-mm specimen failed at 558°C. Another vital parameter studied in transient-state tests was the decrease in temperature with the increase in sustained load. An example of this is the 20-mm specimens which failed at 352 and 258°C, while they were preloaded to 40 and 60% of their capacities. The conclusions of this study suggest that FRCM materials do retain a non-negligible strength capacity at high temperatures. However, further investigations to reveal FRCM bond behaviour and retrofitted structural members at high temperatures are still required to provide comprehensive knowledge.

To successfully develop a functional tissue-engineered vascular patch, recapitulating the hierarchical structure of vessel is critical to mimic mechanical properties. Here, we use a cell sheet engineering strategy with micropatterning technique to control structural organization of bovine aortic vascular smooth muscle cell (VSMC) sheets. Actin filament staining and image analysis showed clear cellular alignment of VSMC sheets cultured on patterned substrates. Viability of harvested VSMC sheets was confirmed by Live/Dead® cell viability assay after 24 and 48 hours of transfer. VSMC sheets stacked to generate bilayer VSMC patches exhibited strong inter-layer bonding as shown by lap shear test. Uniaxial tensile testing of monolayer VSMC sheets and bilayer VSMC patches displayed nonlinear, anisotropic stress-stretch response similar to the biomechanical characteristic of a native arterial wall. Collagen content and structure were characterized to determine the effects of patterning and stacking on extracellular matrix of VSMC sheets. Using finite-element modeling to simulate uniaxial tensile testing of bilayer VSMC patches, we found the stress-stretch response of bilayer patterned VSMC patches under uniaxial tension to be predicted using an anisotropic hyperelastic constitutive model. Thus, our cell sheet harvesting system combined with biomechanical modeling is a promising approach to generate building blocks for tissue-engineered vascular patches with structure and mechanical behavior mimicking native tissue.

Many research studies made on hundreds of MSE walls have shown that in order to get lower values of lateral earth pressure coefficients from an active condition on the backfill soil, thus lower exerted loads and stresses on the reinforcement, the wall needs to yield. This is typical of extensible polymer-based wall systems, such as geosynthetics. Steel systems, on the other hand, are very rigid and do not allow enough deformation on the wall to generate the active condition. For this research, steel reinforcement for MSE walls that behaves similar to geosynthetics was developed. This was done by using crimps on steel bars that would allow the wall to deform as the crimps straighten. A pullout box was designed and constructed, where tensile and pullout tests were performed on the crimped reinforcement. Different crimp geometries on different bar diameters were tested under a range of confining pressures. From this, force-displacement curves were developed for these crimp geometries that could be used to predict deflections on walls with crimped reinforcement. In addition, the pullout resistance of the crimps in the straighten process was evaluated. This way, the crimps would not only be used to allow the wall to yield, but also as a pullout resistance mechanism. The pullout resistances per crimp for different tensions on the crimp and under a range of overburden pressures were evaluated. By combining the pullout resistance of the crimps and the force-displacement curves, a new internal stability design method was introduced where crimped reinforcement is used to resist both pullout and rupture failure. Also presented here are the pullout resistances of round bars with improved deformations of different diameters. These were found to have the same pullout resistance of square deformed bars with the same cross-sectional area. Round bars are preferred over square bars because they are more corrosion resistant and have longer design life.

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Indiana University-Purdue University Indianapolis (IUPUI) / Aluminum extrusion is a metal forming process used for the production of a large variety of solid, semi-solid and complex hollow products. During extrusion, the hot aluminum billet goes under severe plastic deformation as it is forced to flow through a smaller die cavity that defines the final shape of the extruding product. Surface finish and dimensional accuracy are the two most important criteria that specify the productivity and feasibility of the extrusion process which is highly influenced by the flow of aluminum through the deforming die. Therefore, die design is considered as one of the most important characteristics of the extrusion process that influences aluminum flow, quality of the extruding product and its dimensional accuracy. Currently, development of extrusion dies is primarily based upon the empirical knowledge of the die designer gained through trial and error, which inevitability is an expensive, time consuming and ineffective method. However, owing to the technological advancements of this century in the field of finite element modeling, this decade old trial and error method can now be replaced by numerical simulations that not only save time and money but also, can accurately predict the flow of aluminum through a die as well as predict die deformation occurring during the extrusion process The motivation of this research project came from a private extrusion die manufactures need for improving their pioneered modular die based on good analytical and scientific understanding of the dies performance during the extrusion process. In this thesis, a commercial simulation package Deform 3D is used to simulate the thermo-mechanical interactions of aluminum flow through the deforming modular die for the production of Micro Multi-Port (MMP) tubes.

Indiana University-Purdue University Indianapolis (IUPUI) / Acrylonitrile Butadiene Styrene (ABS) is the most widely used thermoplastics in 3D printing for making models, prototypes, patterns, tools and end-use parts. However, there is a lack of systematic understanding of the mechanical properties of 3D printed ABS components, including orientation-dependent tensile strength, creep, and fatigue properties. These mechanical properties are critically needed for design and application of 3D printed components. The main objective of this research is to systematically characterize key mechanical properties of 3D printed ABS components, including tensile, creep, and fatigue properties. Additionally, the eff ects of printing orientation on the mechanical prop- erties are investigated. There are two research approaches employed in the thesis: rst, experimental investigation of the tensile, creep, and fatigue properties of the 3D printed ABS components; second, laminate based finite-element modeling of tensile test to understand the stress distributions in different printing layers. The major conclusions of the thesis work are summarized as follows. The tensile test experiments show that the 0 printing orientation has the highest Young's modulus, 1.81 GPa, and ultimate strength, 224 MPa. The tensile test simulation shows a similar Young's modulus as the experiment in elastic region, indicating the robustness of laminate based finite element model. In the creep test, the 90 printing orientation has the lowest k value of 0.2 in the plastics creep model, suggesting the 90 is the most creep resistant among 0 , 45 , and 90 printing orientations. In the fatigue test, the average cycle number under load of 30 N is 3796 revolutions. The average cycle number decreases to 128 revolutions when the load is below 60N. Using the Paris Law, with the crack size of 0.75 mm long and stress intensity factor is varied from 352 to 700 MN -m^3/2 , the predicted fatigue crack growth rate is 0.0341 mm/cycle.