As part of the research colloquium for final theses, doctoral and postdoctoral students, we cordially invite you to the lecture:

Daniela Masarczyk M.Sc.

"Sustainability in bridge design - investigation of the potential of topology optimization and additive manufacturing on a model scale"

This research work was developed in cooperation with Mr. Tizian Arold M.Sc. from the Institute of Materials Engineering of the Faculty of Mechanical Engineering.

Tuesday, 18.06.2024, Mö 7, room 3516, 16.00 hrs.

We look forward to seeing you there!

Abstract

In the context of sustainable construction in civil engineering and considering the increasing cost of building materials, the design of resource-efficient structures is a key challenge. Mechanical efficiency in structural design ensures that the building materials are used where necessary to support a given load. The design process can be assisted by numerical structural optimization. The manufacturability of optimized structures represents a challenge due to their free, usually non-rectangular shape.

Aim of the present study is to investigate the potential of additive manufacturing (AM) for therealization of optimized bridge models. Bridges are subject to high structural loads, a large part of which is induced by the self-weight of the bridge and therefore needs to be considered in the design process. Numerical topology optimization with consideration of self-weight is used to design the structural layout. Objective of the optimization is structural stiffness with a bound on the disposable amount of material. The popular SIMP method, modified for consideration of self-weight, is used to interpolate the material stiffness. The highly non-linear optimization problem is solved by a custom topology optimization routine that is based on Sequential Quadratic Programming and written in Matlab. The optimized structural layouts are transferred to a CAD model to enable fabrication by AM.

The optimization results show a strong similarity to already existing arch bridges. A support structure based on an inverted catenary is observed in the resulting structures. The arch and the bridge deck are connected by structures that are likewise subjected to their own weight; therefore, their shape is also based on the catenary which represents a new feature to be incorporated in bridge design. Prototypes of the optimized bridges will be manufactured on a small scale by means of AM methods based on the powder bed technique. The bridge models are presented and examined, structural design and the potential of AM for the fabrication of optimized structures in civil engineering are evaluated.