Supervisor: David Ohlsson, Material and Production , Additive Manufacturing, Department of Manufacturing Processes , RISE IVF
Supervisor and Examiner: Ragnar Larsson, IMS
Additive Manufacturing (AM) for metals is a rapidly growing area on the brink of its industrialization. From a structural design perspective, topology and parameter optimization are favorable design tools; however, the standard manufacturing technologies, like casting, often limits the applicability of these tools. A great advantage with the AM is that the manufacturing constraints for AM are relatively free as compared to other manufacturing methods. One way of utilizing the potential of AM is to integrate a lattice structure in the structural design.
The lattice structure can be of different shapes, for instance truss-like shape or gyroid mesh. By using low density lattice structures as infill to a shell structure (instead of solid material) a light and strong structure can be obtained. Lattice structures are usually used as temporary support structures which are removed after the print but here, they will serve
an additional purpose, namely as part of the load bearing structure. This master thesis conducted at RISE IVF consists of first studying various types of self-supporting lattices and conducting virtual tests with regard to shear, tension, compression stresses etc. The second part of the thesis concerns topology optimization of a structural component design provided by Volvo Cars. This is done in order to get a design output that is suitable to be integrated with lattice structure to achieve lightweighting with minimal changes to the strength characteristics. A homogenized model is developed to verify the effects of the lattice unit cell in the optimized component.
The final results of the linear analysis of the homogenized model was compared to the linear analysis of the steel sheet metal pivot bracket given by Volvo Cars. The final result comparison and analysis showed that the topology optimized pivot bracket component with integrated lattice structure was slightly lighter than the steel sheet metal pivot bracket designed by Volvo Cars and of comparable stiffness. This methodology allowed the authors to create a component design that is integrated with lattice structure and has a comparative stiffness design parameter of the original component. The design is also potentially manufacturable by AM, but the time limit prevented the actual printing process and hence all results were verified virtually. This methodology can be used for components that are fit for manufacturing via additive manufacturing lightweighting without much loss of structural integrity .
Keywords : Unit Lattice Cell, Topology Optimisation, Lattice Optimisation, Homogenisation, Additive Manufacturing .
Student project presentation
18 September, 2020, 13:00
18 September, 2020, 14:00