Adding a New Dimension to Glass Giants

Abstract

This thesis is part of a larger ongoing research project at the TU Delft regarding structural glass as a novel construction material. Here, the focus is directed towards the casting of glass to create complex free-form geometries. Thus far, only smaller components have been created, but a multitude of previous student work explored how the current limitations in the fabrication process could be overcome by using topology optimization to design larger cast glass components. This thesis continues this research by integrating the limitations and remarks concluded from previous work to further explore the potential of designing large cast glass components using topology optimization.

This thesis intends to contribute to the existing research by creating a tool for the design of 3D optimized cast glass components, which can take into consideration the structural properties of glass as well as manufacturing, annealing and specific design criteria. The tool is created in Matlab, using the SIMP optimization method with 8-noded hexahedral finite elements for the structural model.

From the literature review it was concluded that the SIMP methodology is best suited the requirements of this project. For the structural model, 8-noded hexahedral elements were selected. Two algorithms were developed: one with a compliance based objective and a second with a volume based objective.

The algorithm’s performance was tested on different domains. To facilitate comparison with existing literature, the algorithm was initially calibrated with a domain width of one element, effectively creating a two-dimensional optimization. Subsequently, its performance was assessed through the application of a small three-dimensional problem. Finally, the algorithm is used to design a case study involving the structural slab of a small pedestrian bridge located inside the British Museum.

The results validate the benefits of the 3D algorithm. The geometries optimized in three dimensions have a higher structural stiffness and offer more spatial insight. Moreover, the volume optimizations results in a larger material reduction than those achieved in two-dimensional optimizations. For this reason, the volume-optimized component was selected for post-processing and implementation in the final design.