Application of WAAM to build functional components: topology improvements and intersection construction
2020 (engelsk)Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hp
OppgaveAlternativ tittel
Tillämpning av WAAM för att bygga funktionella komponenter : förbättringar av topologi och konstruktion av korsningar (svensk)
Abstract [en]
Wire plus arc additive manufacturing (WAAM) is an additive manufacturing process with considerable possibilities of engendering actual functional components (due to high deposition rates), which consume less energy to do the same work, and reduce the cost of the material. WAAM is feasible in terms of the geometrical design of the structure to be fabricated, but to triumph at the design used for deposition of an actual functional component, it has to undergo virtual mechanical loading tests, or, also called as simulations. Simulations can be used to decide the design parameters to be altered for a proficient design. Therefore, the aim of the first stage of work was to ascertain that the truss structure, is lighter when compared to the block structure, provided, both the structures are subjected to same load condition and the total displacement values reclaimed from both the structures, are also the same. The numerical simulations were performed using a structural analysis software with five sub-stages of the work development. (i) Modelling; (ii) Material and Structural Analysis; (iii) Simulation parameters; (iv) Simulations; (v) Mass calculations. Simulations and mass calculations have proved that the truss structure was in fact lighter when compared to the block structure. Therefore, the truss structure can be fabricated using WAAM because of the favourable advantage. But the parameters such as current, speed of the robot while depositing, the shape of the truss structure etc., were required for the deposition. Also, the behaviour of the molten metal at the intersection region (the area where the truss and the frame meet) is a major concern because either the frame deposited over the truss or the truss deposited over frame, will be responsible for material accumulation (supplementary amount of molten metal solidifies in a particular region) at the intersection region. So, the decision of the parameters and analysis on material accumulation was made in the second stage of work. The second stage required few pre-requisite experiments to be performed before designing a plan. There were two prerequisite experiments performed in which one was to find the minimum distance from the lateral edge of the base plate, at which the deposition can be done, and the other was to find the shape of the truss. The first experiment had a motive to define the dimensions of the base plate on which the fabrication of the truss structure will be done using WAAM. The second experiment was to decide the shape that can be used for deposition with minimum material accumulation at the vertex of the truss. Both the experiments were successful in providing the minimum distance and shape, respectively. The second work stage was performed to study the intersection region between the truss and the frame. Ample number of depositions were done using different deposition parameters, such as current and different distances between the centrelines of the truss and frame. Visual and optical analysis was done to find the common trends in the samples. The intersections in a sample were classified in to good and bad based on visual inspection. The samples were cut cross-sectionally for optical analysis so that imperfections present, if any, can be pointed out. Finally, material accumulation was assessed with the volumetric calculations, using the measurements done at the intersection region. As a conclusion, this approach has provided the design for topological enhanced structure and the parameters required to deposit it using WAAM process.
sted, utgiver, år, opplag, sider
2020. , s. 111
Emneord [en]
WAAM, Simulation, truss structure, parametric set
HSV kategori
Identifikatorer
URN: urn:nbn:se:hv:diva-15988Lokal ID: EXM902OAI: oai:DiVA.org:hv-15988DiVA, id: diva2:1477854
Fag / kurs
Mechanical engineering
Utdanningsprogram
Masterprogram i tillverkningsteknik
Veileder
Examiner
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