In Automotive and Aerospace industries, Topology Optimization (TO) is being used for the last few decades to produce lightweight structures. On the other hand, TO produces very complex geometrical features (i.e. irregular shape and hidden cavities along the thickness) that is sometimes difficult to be manufactured even with Additive Manufacturing (AM) and Casting techniques. In this paper suitable design and manufacturing constraint (MC) are applied during TO process that act as an Optimization Tool (OT) and improves geometrical features of the mechanical structures for easy manufacturing. Three mechanical structures with different geometries and boundary conditions have been considered for analysis purpose. Topology Optimization based on linear static analysis has been performed using OptiStruct (HyperWorks) solver. Finally, results of analysis conclude that the proposed OT produces lightweight structures with very simple geometries that can easily be manufactured with the help of AM or Casting techniques.

For the past few decades, topology optimization (TO) has been used as a structural design optimization tool. With the passage of time, this kind of usage of TO has been extended to many application fields and branches, thanks to a better understanding of how manufacturing constraints can achieve a practical design solution. In addition, the advent of additive manufacturing and its subsequent advancements have further increased the applications of TO, raising the chance of competitive manufacturing. Design for additive manufacturing has also promoted the adoption of TO as a concept design tool of structural components. Nevertheless, the most frequent applications are related to lightweight design with or without design for assembly. A general approach to integrate TO in concept designs is still missing. This paper aims to close this gap by proposing guidelines to translate design requirements into TO inputs and to include topology and structural concerns at the early stage of design activity. Guidelines have been applied for the concept design of an inner supporting frame of an ancient bronze statue, with several constraints related to different general design requirements, i.e., lightweight design, minimum displacement, and protection of the statue’s structural weak zones to preserve its structural integrity. Starting from the critical analysis of the list of requirements, a set of concepts is defined through the application of TO with different set-ups (loads, boundary conditions, design and non-design space) and ranked by the main requirements. Finally, a validation of the proposed approach is discussed comparing the achieved results with the ones carried out through a standard iterative concept design.

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Spinal deformity is a disease that causes a three-dimensional deformation of the spinal column. When it worsens, surgery is required to screw correction rods to the spinal column. However, the surgery requires intraoperative rod bending work, which burdens the patients and causes unexpected rod breakage inside the body. Therefore, "pre-bent" rods comprising several rods with standardized shapes have been proposed to solve these problems. When designing pre-bent rods, knowing the number of rods to be prepared and the kinds of shapes required is essential. In this paper, we propose a geometric processing technique to identify an optimal set of these standardized pre-bent rod shapes for surgeries on adult spinal deformity and describe the similarity evaluation among existing rod shapes using CT scan, medial axis extraction, and iterative closest point algorithm. Moreover, we present the derivation of standardized rod shapes using hierarchical cluster analysis and the best fit of the B-spline curve to each cluster. Finally, we discuss the effectiveness of prebent rod shapes derived from CT scans of 26 existing rods of 13 patients.

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