A.J. Martínez-Donaire

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.

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

Teaching and Learning of Manufacturing Engineering through Virtualization of Processes on CNC Machines

This paper presents the latest developments in a digital documentation project related to manufacturing processes on machine tools. The project is supported by engineering students doing their bachelor/master thesis within this field. Different virtual models have been developed by using CATIA V5, such as conventional and CNC machines, several parts to be manufactured, and different manufacturing processes such as machining, incremental sheet forming and 3D printing. Some of the modelled parts have been manufactured. The developed digital documentation is used as supplementary material in subjects of bachelor and master degree in Industrial/Aerospace Engineering, with a high degree of acceptance by students.

Teaching & Learning of Sheet Metal Forming Processes Using DEFORM-3D

The aim of this paper is to analyze the use of Finite Element Analysis (FEA) in the teaching-learning strategy of metal forming processes. To this end, students are proposed to use the commercial package DEFORM-3D® for the development of their bachelor and master theses within the research line on incremental sheet forming processes. The student acquires skills and competencies on numerical simulation and design of real metal forming processes valuable for their future professional practice, while strengthening the foundations of these manufacturing technologies. This proposal is consistent with the active teaching methodologies included in the guidelines of the European Higher Education Area (EHEA).

Experimental Study of the Formability of H240LA Steel Sheets under Stretch-Bending Conditions

The present work discusses the effect of the punch radius on the formability of H240LA steel sheets of 1.2mm thickness. A series of hemispherical punch tests (Nakazima tests) and stretch-bending tests with cylindrical punches of different diameters have been carried out in order to characterize the influence of the strain gradient in the sheet failure. The limit strains have been obtained using a recently proposed time-dependent methodology, which is applicable not only in conventional Marciniak and Nakazima tests, but also in situations with a severe strain gradient through the sheet thickness. The results show that formability of H240LA steel sheets increases as the t0/R ratio decreases.