Form-Finding and Structural Shape Optimization of the Metal 3D-Printed Node

In the last few years, considerable attention has been paid to additive manufacturing (AM) technologies to redesign and modify the industrial products with regard to its merits. At the initial stage of technology development, AM was mostly used as a building platform for prototyping, whereas its usage has been recently extended to industrial applications. Amid the different methods of AM technology, the development of metal AM, in particular, Powder Bed Fusion (PBF) and metal Binder Jetting (MBJ), facilitate the production of high-quality and complex parts in several sectors of industry such as aerospace, medical, architecture and civil engineering. Understanding the novel advantage of metal 3D-printing in the development of high-performance and functional parts for applications in the construction sector enables researchers to propose different design and form-finding methods for construction components

Design and Robotic Fabrication of 3D Printed Moulds for Composites

3D printing technologies have a direct impact on manufacturing the composite structures and in particularly fabrication of molds. Molds produced through additive manufacturing methods would greatly improve product features. The material selection and process conditions involved for producing mold tooling, mainly towards Automated fiber placement (AFP) work cells. In this study, the main objective is to improve the design and fabrication of composite parts through complex molds as well as to assess and improve the production workflow through the development of an effective design environment for the existing fiber placement operation. A robotic arm will be used to hold the print surface and to follow a pre-programmed print path with a stationary extruder to fabricate the mold tooling. This paper will present a review on the selection process for mold materials and the initial experimental work carried out to investigate required properties of 3D printed molds.Mechanical Engineerin

Fabrication of complex 3D composites by fusing automated fiber placement (AFP) and additive manufacturing (AM) technologies

Automated fiber placement (AFP) is emerging as one of the advanced methods toward fabrication of polymer matrix based composite structures. This automated technique focuses on polymer composite manufacturing for use in a wide range of automotive and aerospace applications. The AFP process offers an elevated level of customization through the possibility of placing each individual tow at custom-designed trajectories. Additive manufacturing (AM) method, on the other hand, has the potential to fabricate functional end user parts of complex geometries, thus eliminating the need for costly tooling, multi-step processing and fasteners or joints. This paper will highlight the potential of fusing AFP and AM processes to fabricate complex 3D polymer based composite parts. A combination of these two processes suggests a promising option for composite materials development, improving composite structures in terms of complexity and customizability. The paper presents the adopted research methodology, background research, the design, development and set up of an experimental workcell that fuses AM and AFP, and the design methodology which is required to design complex composite parts using the proposed manufacturing process. Main challenges and opportunities are discussed, such as how restrictions of conventional composite production can be eased, and additional freedoms of design can be achieved

A Comprehensive Review on Bio-Nanomaterials for Medical Implants and Feasibility Studies on Fabrication of Such Implants by Additive Manufacturing Technique

Nanomaterials have allowed significant breakthroughs in bio-engineering and medical fields. In the present paper a holistic assessment on diverse biocompatible nanocomposites are studied. Their compatibility with advanced fabrication methods such as additive manufacturing for the design of functional medical implants is also critically reviewed. The significance of nanocomposites and processing techniques is also envisaged comprehensively in regard with the needs and futures of implantable medical device industries

Form-Finding and Structural Shape Optimization of the Metal 3D-Printed Multi-Branch Node with Complex Geometry

The application of additive manufacturing (AM) technology in architecture and structural engineering has been extended due to recent development of metal 3d printing. In space frame structures, a set of bars is configured in three dimensions, with bars connected by nodes. This article presents two methods to design metal 3d-printed multi-branch nodes to accommodate any number of incident bars at arbitrary angles. Resulting node designs are intended to be smooth and lightweight. A multi-branch node is sketched using the dimensional information of the blank space between the converging bars in a pre-designed space frame and then parameterized by two different approaches to perform structural optimization. The first design method, namely the curve parameter method, which is semi-automated approach, the distances between the control points of the spline curves between node branches and the node branch intersection point are the optimization parameters. For the other method, called fatness parameter method, which is a fast and automated approach, the fatness parameters of the center part of the node and the root radiuses of each branch are chosen as the main parameters of optimization. The optimization procedure is accomplished using a genetic algorithm to minimize the maximum von Mises stress as the objective function subjected to the mass of the node as a constraint function. Finally, functional tests are conducted on 3D printed metal nodes in order to compare the strength and stiffness of the nodes designed by the two form-finding approaches