D. Morales-Palma

A functional methodology on the manufacturing of customized polymeric cranial prostheses from CAT using SPIF

Purpose This paper aims to propose a functional methodology to produce cranial prostheses in polymeric sheet. Within the scope of rapid prototyping technologies, the single-point incremental forming (SPIF) process is used to demonstrate its capabilities to perform customized medical parts. Design/methodology/approach The methodology starts processing a patient’s computerized axial tomography (CAT) and follows with a computer-aided design and manufacture (CAD/CAM) procedure, which finally permits the successful manufacturing of a customized prosthesis for a specific cranial area. Findings The formability of a series of polymeric sheets is determined and the most restrictive material among them is selected for the fabrication of a specific partial cranial prosthesis following the required geometry. The final strain state at the outer surface of the prosthesis is analysed, showing the high potential of SPIF in manufacturing individualized cranial prostheses from polymeric sheet. Originality/value This paper proposes a complete methodology to design and manufacture polymer customized cranial prostheses from patients’ CATs using the novel SPIF technology. This is an application of a new class of materials to the manufacturing of medical prostheses by SPIF, which to this purpose has been mainly making use of metallic materials so far. Despite the use of polymers to this application is still to be validated from a medical point of view, transparent prostheses can already be of great interest in medical or engineering schools for teaching and research purposes.

Teaching Experience for the Virtualization of Machine Tools and Simulation of Manufacturing Operations

This work aims to generate the digital documentation related to a number of manufacturing processes on different machine tools. The project is developed with the contribution of engineering students doing their final thesis within this field. Different machine tools and machining and incremental forming processes have been virtualized by using the CAD/CAM software CATIA V5. Some of the modeled parts were finally manufactured after checking and post-processing the NC code. Digital documentation is developed on different formats (e.g. photographs, videos, images and simulations) in order to be used as a teaching complement.

Multidisciplinary Learning of Manufacturing Engineering through Bachelor and Master Theses in Incremental Sheet Forming

This work presents a novel teaching experience in the framework of final master and bachelor theses within the research line on incremental sheet forming processes. This forming process involves a series of competences dealing with manufacturing technology at a wide multidisciplinary level. This paper analyses these different manufacturing topics and the knowledge acquired by students doing their final theses within this field. This knowledge will be very useful during their future professional career.

Self-Evaluation E-Learning System for Manufacturing Engineering Subjects

This work presents a project of teaching innovation on the subject Technology of Manufacturing that has been developed for the last five years. The objective is to stimulate students for training through a self-evaluation system based on e-learning tools, in agreement with the guidelines of the European Higher Education Area (EHEA). The system includes a methodology to perform a series of evaluations about theoretical and practical knowledge which allows the student self-learning. The data obtained with the proposed system are analyzed and the effect on student results is discussed. The evolution in time of the student grades, their involvement and satisfaction with the project, and its influence in their final score are presented.

Teaching Experience on Metal Forming Processes through Case Study Methodology

The aim of this contribution is to promote the use of FEM based numerical simulations for teaching the fundamentals of manufacturing processes. In particular, it focuses on metal forming processes, which by their mathematical modelling complexity can only be tackled in a very elementary way using traditional methods. This enables an active teaching based on realistic problem solving, through which students acquire both theoretical and practical knowledge on the subject. This approach is consistent with the guidelines of the European Higher Education Area (EHEA) on the use of participatory learning tools.

Managing Maturity States in a Collaborative Platform for the iDMU of Aeronautical Assembly Lines

Collaborative Engineering aims to integrate both functional and industrial design. This goal requires integrating the design processes, the design teams and using a single common software platform to hold all the stakeholders contributions. Airbus company coined the concept of the industrial Digital Mock Up (iDMU) as the necessary unique deliverable to perform the design process with a unique team. Previous virtual manufacturing projects confirmed the potential of the iDMU to improve the industrial design process in a collaborative engineering environment. This paper presents the methodology and preliminary results for the management of the maturity states of the iDMU with all product, process and resource information associated with the assembly of an aeronautical component. The methodology aims to evaluate the suitability of a PLM platform to implement the iDMU in the creation of a control mechanism that allows a collaborative work.

Novel experimental techniques for the determination of the forming limits at necking and fracture

Abstract Forming limit diagrams (FLDs) are currently the most useful and used tool for evaluating the workability of metal sheets. FLDs provide the failure locus at the onset of necking (commonly designated as the forming limit curve [FLC]) and at the onset of fracture in the principal strain space. The FLC is usually determined by means of Nakazima and Marciniak tests following the ISO 12004-2:2008 standard but the procedure for evaluating the necking strains presents difficulties that often lead to the fact that FLCs of the same material provided by different sources present sensible differences from each other. The interest in the determination of the onset of fracture has always been limited because most of the conventional sheet metal forming processes reach their formability limits at the onset of necking. However, this trend is progressively changing as a result of the growing interest and rapid development of new increment sheet forming processes in which plastic deformation is successfully accomplished for strain loading paths well above the FLC. On the other hand, a recently developed analytical framework built upon the fundamental concepts of anisotropic plasticity, ductile damage, and fracture mechanics helps better understanding of the relation between formability limits by fracture and crack opening modes. Both fracture limits by tension (also known as the fracture forming limit line [FFL]) and by in-plane shear (also known as the shear fracture forming limit line [SFFL]) will be characterized and experimentally determined. This chapter focuses on the innovative methods and procedures that were recently developed by the authors for the determination of the formability limits by necking (FLC) and fracture (FFL/SFFL), and on the application of FLDs to stretch-bending and single-point incremental forming processes. Results are comprehensively described and illustrated by a series of examples retrieved from experimental testing on steel and aluminum alloys and allow understanding of the influence of bending on formability.

Optimization of Hole-Flanging by Single Point Incremental Forming in Two Stages

Single point incremental forming (SPIF) has been demonstrated to accomplish current trends and requirements in industry. Recent studies have applied this technology to hole-flanging by performing different forming strategies using one or multiple stages. In this work, an optimization procedure is proposed to balance fabrication time and thickness distribution along the produced flange in a two-stage variant. A detailed analytical, numerical and experimental investigation is carried out to provide, evaluate and corroborate the optimal strategy. The methodology begins by analysing the single-stage process to understand the deformation and failure mechanisms. Accordingly, a parametric two-stage SPIF strategy is proposed and evaluated by an explicit Finite Element Analysis to find the optimal parameters. The study is focused on AA7075-O sheets with different pre-cut hole diameters and considering a variety of forming tool radii. The study exposes the relevant role of the tool radius in finding the optimal hole-flanging process by the proposed two-stage SPIF.

Experimental and numerical analysis of the flanging process by SPIF

Altair Engineering, Inc.,Amada Foundation,AutoForm Engineering GmbH as Platinum and Dinner,et al.,ITOCHU Techno-Solutions Corporation,JSOL Corporation

Value Chain: From iDMU to Shopfloor Documentation of Aeronautical Assemblies

Competition in the aerospace manufacturing companies has led them to continuously improve the efficiency of their processes from the conceptual phase to the start of production and during operation phase, providing services to clients. PLM (Product Lifecycle Management) is an end-to-end business solution which aims to provide an environment of information about the product and related processes available to the whole enterprise throughout the product’s lifecycle.