Lattice structures for engineering applications are patterns of unit cells designed to make a larger functional structure. Research on lattice structures ranges in many fields, from mechanical characterization and cell and pattern designs in respect of their applications, to the manufacturing process and its final shape control. From the manufacturing point of view, some kinds of lattice structures can be infeasible when approached with traditional manufacturing methods. It may offer an inevitable limitation of their adoption. However, advancements in Additive Manufacturing (AM) have solved this manufacturing issue to a great extent, allowing to obtain major complexity of the cells that can be achieved. The topology, shape of the unit cell, and the characteristics of its replication pattern allow us to obtain many kinds of structures in respect of the different engineering requirements and manufacturing constraints. Nevertheless, the necessity of new or dedicated CAD-CAE approaches arises to manage the domains of multiscale modeling. These are some of the advantages and disadvantages that may arise while approaching the design of a component using lattice structures. The aim of this paper is to provide an overview that integrates the most recent applications of lattice structures with their related design and manufacturing issues so that, from a practical design point of view, any state-of-the-art improvements may be established in respect of the related field of applications. In this article, engineers and researchers may find a practical summary of the capabilities and processes of lattice structures that are currently available from a design and development point of view.

This paper presents a point cloud segmentation based on a spatial multiresolution discretisation that is derived from hierarchical space partitioning. Through part type recognition it aims to simplify Computer Aided Tolerance Inspection of electromechanical components avoiding cloud-CAD model registration. A voxel structure subdivides the point cloud. Then, through a suitable surface partitioning, it is linked to component volumes by means of the morphological components of the binary image that is derived from voxel attributes (‘true state’ if points are included in a specific cluster or ‘false state’ if they are not). The proposed approach is then applied on a din-rail clip of a breaker, made by injection moulding. This case study points out the suitability of the approach on box-shaped components or with normal protrusions, and its limits concerning the assumptions of the implementation.

The use of continuum mechanics, especially Finite Element Analysis (FEA) has gained an extensive application in the medical field, in order to simulate soft tissues. In particular, colorectal simulations can be used to understand the interaction between colon and the surrounding tissues, and also, between colon and surgical instruments. Although several works have been introduced considering small displacements, FEA applied to colorectal surgical scenarios with large displacements is still a challenge. This work aims to investigate how FEA can describe non-linear effects induced by material properties and different approximating geometries for colon. More in detail, it shows a comparison between simulations that are performed using well-known hyperelastic models (principally Mooney-Rivlin and, in one case, Yeoh) and the linear one. These different mechanical behaviours are applied on different geometrical models (planar, cylindrical and a 3D-shape from digital acquisitions) with the aim of evaluating also the effects of geometric non-linearity. Increasing the displacements imposed by the surgical instruments, the adoption of a hyperelastic model shows lower stresses than the linear elastic one that seems to overestimate the averaged stress. Moreover, the details of the geometrical models affect the results in terms of stress-strain distribution, since it provides a better localisation of the effects related to the hypothesis of large strains.

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.