Search results for "Forming."
showing 10 items of 1704 documents
Multi Stage Strategies for Single Point Incremental Forming of a Cup
2008
A five stage forming strategy for Single Point Incremental Forming of a circular cylindrical cup with a height/radius ratio of one is presented. Geometrical relations are discussed and theoretical strains are calculated. The influence of forming direction (upwards or downwards) is investigated for the second stage comparing explicit FE analysis with experiments. Good agreement is found between calculated and measured thickness distribution, overall geometry and strains. Using the proposed multi stage strategy it is shown possible to produce a cup with a height close to the radius and sides parallel to the symmetry axis in about half of the depth.
Error Estimates and Automatic Adaptive Mesh Refinement for the Metal Forming FEM Analysis
1988
The Authors propose a new technique which enables a estimation of the error inherent with the FEM analysis of metal forming processes. The aim is to evaluate the zones where the error is higher in order to proceed to a refinement of the mesh in such zones, and to obtain a smaller value of the global error. Moreover, to simplify the analyst work in the progressive refinement of the mesh, it has been prepared a software able to read the drawing created by a CAD program and to generate, automatically, all the geometrical and topological data necessary to perform the analysis on Personal Computer. The automatic renumbering of the elements in the refined mesh has been performed with the aim to r…
Common defects of parts manufactured through single point incremental forming
2021
Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final g…
Diverse histories, common ground and a shared future:the education of career guidance and counselling professionals in the Nordic countries
2019
The development of education programmes in career guidance and counseling (CGC) has followed different paths among the various Nordic countries. Ten CGC programmes in Denmark, Finland, Greenland, Iceland, Norway and Sweden were evaluated against the NICE curricular model. The results show that all NICE core competences are represented in the curricula. However, there is greater focus in some programmes on developing competences for individual career guidance, than on developing competences for working at organisational and societal levels. Implications for the cooperation and professionalisation of CGC within the Nordic countries are discussed as well as limitations of the NICE model. Keywo…
Evaluation of Guidance Services in Higher Education in Finland
2003
The Finnish Higher Education Evaluation Council (FINHEEC) implemented an evaluation of guidance services in higher education in 2000–2001. Altogether 25 higher education institutions participated in the evaluation. This article describes the evaluation process, findings and recommendations. The aim is to show how an evaluation process can serve the development of guidance policies and practices at the institutional and national levels. Additionally, the article demonstrates the use of evaluation methodology as a means of enhancing communication between staff and students.
Influence of expressive versus mechanical musical performance on short-term memory for musical excerpts
2012
Recognition memory for details of musical phrases (discrimination between targets and similar lures) improves for up to 15 s following the presentation of a target, during continuous listening to the ongoing piece. This is attributable to binding of stimulus features during that time interval. The ongoing-listening paradigm is an ecologically valid approach for investigating short-term memory, but previous studies made use of relatively mechanical MIDI-produced stimuli. The present study assessed whether expressive performances would modulate the previously reported finding. Given that expressive performances introduced slight differences between initially presented targets and their target…
Neural Network Techniques for Metal Forming Design
1993
Neural networks are computing structures able to predict the behaviour of a system on the basis of the knowledge of facts; main characteristic of a network is the capability to find a rule in a very complex environment. In the paper a neural network, based on the results of FEM simulations, is utilized to predict the occurrence of defects in a forward extrusion metal forming process. In particular a three layers neural network, relating the operative parameters with the failure or the success of the working process, has been used and the back-propagation algorithm has been employed to train the network. Few experimental data were enough to train the neural network allowing to achieve better…
H and P Mesh Refinement in the Metal-Forming F.E.M. Analysis
1988
In this paper a comparison between H and P refinement techniques in the metal-forming F.E.M. analysis is carried out in order to evaluate their computational efficiency. The results are compared using a particular error estimator which locally allows determining the workpiece zones where the refinement is necessary.
Forming Processes Design Oriented to Prevent Ductile Fractures
1996
During cold forming processes ductile fractures are sometimes encountered, depending on the operating parameters and on the material properties and determining the production of defective components to be discarded; for this reason the development of a general approach for the prediction of this type of defects is particularly suitable and this aim has been pursued by a large number of researchers in the last two decades. In the paper the most important and diffused models are described and analysed in order to outline the advantages offered by each of them. Some applications to typical metal forming processes are presented, carrying out a comparison between the numerical predictions and th…
Mitochondrial dynamics in type 2 diabetes: Pathophysiological implications
2017
Mitochondria play a key role in maintaining cellular metabolic homeostasis. These organelles have a high plasticity and are involved in dynamic processes such as mitochondrial fusion and fission, mitophagy and mitochondrial biogenesis. Type 2 diabetes is characterised by mitochondrial dysfunction, high production of reactive oxygen species (ROS) and low levels of ATP. Mitochondrial fusion is modulated by different proteins, including mitofusin-1 (MFN1), mitofusin-2 (MFN2) and optic atrophy (OPA-1), while fission is controlled by mitochondrial fission 1 (FIS1), dynamin-related protein 1 (DRP1) and mitochondrial fission factor (MFF). PARKIN and (PTEN)-induced putative kinase 1 (PINK1) partici…