DEVELOPMENT OF A TOPOLOGY OPTIMIZATION ALGORITHM WITH ADDITIVE MANUFACTURING CONSTRAINTS

Resumo

Topology Optimization (TO) is a systematic method with wide application to structural
optimization. TO combines optimization algorithms with finite element method, in order to provide an
optimal material distribution inside a design domain, aiming to attend a specified objective function and
to satisfy the constraints on the optimization problem. Additive Manufacturing (AM) is a generalized
term utilized to designate the manufacturing techniques, that employ the principle of fabrication by
adding material layer by layer to obtain the final geometry of a product. This principle is powerful for
manufacturing geometries of higher complexity when compared to traditional manufacturing
techniques, such as machining, forging and others. Although AM techniques have a high capacity of
producing TO geometries, without compromising to much its optimality, these techniques still have
manufacturing restrictions. Feasible AM geometries have associated requirements such as minimum
member size, minimum overhang angle and minimum hole size, for instance. The aim of this work is to
develop a structural optimization algorithm, including in the formulation of the TO problem a
projection-based filter which implicitly applies a manufacturing constraint imposed by the AM
manufacturing process known as FDM (Fused Deposition Modelling), whose technique possess a
critical overhang angle at which the structure does not self-supports. In this case, a projection function
and variable mappings are defined to impose the maximum overhang constraint. Specifically, it aims to
avoid or eliminate the support material utilized in the FDM process and, consequently, reduce the
fabrication costs of the process. Some results are presented to demonstrate the potential of the proposed
TO algorithm.