Towards Design Automation for Additive Manufacturing : A Multidisciplinary Optimization approach

In recent decades, the development of computer-controlled manufacturing by adding material layer by layer, called Additive Manufacturing (AM), has developed at a rapid pace. The technology adds possibilities to the manufacturing of geometries that are not possible, or at least not economically feasible, to manufacture by more conventional manufacturing methods. AM comes with the idea that complexity is free, meaning that complex geometries are as expensive to manufacture as simple geometries. This is partly true, but there remain several design rules that needs to be considered before manufacturing. The research field Design for Additive Manufacturing (DfAM) consists of research that aims to take advantage of the possibilities of AM while considering the limitations of the technique. Computer Aided technologies (CAx) is the name of the usage of methods and software that aim to support a digital product development process. CAx includes software and methods for design, the evaluation of designs, manufacturing support, and other things. The common goal with all CAx disciplines is to achieve better products at a lower cost and with a shorter development time. The work presented in this thesis bridges DfAM with CAx with the aim of achieving design automation for AM. The work reviews the current DfAM process and proposes a new integrated DfAM process that considers the functionality and manufacturing of components. Selected parts of the proposed process are implemented in a case study in order to evaluate the proposed process. In addition, a tool that supports part of the design process is developed. The proposed design process implements Multidisciplinary Design Optimization (MDO) with a parametric CAD model that is evaluated from functional and manufacturing perspectives. In the implementation, a structural component is designed using the MDO framework, which includes Computer Aided Engineering (CAE) models for structural evaluation, the calculation of weight, and how much support material that needs to be added during manufacturing. The component is optimized for the reduction of weight and minimization of support material, while the stress levels in the component are constrained. The developed tool uses methods for high level Parametric CAD modelling to simplify the creation of parametric CAD models based on Topology Optimization (TO) results. The work concludes that the implementation of CAx technologies in the DfAM process enables a more automated design process with less manual design iterations than traditional DfAM processes. It also discusses and presents directions for further research to achieve a fully automated design process for Additive Manufacturing.