Search results for "Formability"

Study of the implementation of SPIF as a Reshaping strategy in terms of formability and accuracy performance

2022

The adaption of circular economy strategies has become increasingly necessary in current times. Researches need to be addressed on finding alternative processes or the modification of the existing processes in order to reprocess End-of-Life (EoL) components and consequently recover both materials and their functions. This research paper focuses on the use of single point incremental forming (SPIF) process for the Reshaping of sheet metal EoL components. Uniaxial and biaxial pre-straining was performed on AA5754 sheets to imitate an end-of-life component, and SPIF operations were carried out so as to obtain reshaped components. In previous works, the authors have proven the technical feasibi…

Erythrocyte deformability profile evaluated by laser diffractometry in patients with multiple myeloma: Re-examination of our cases.

2023

Background: Multiple myeloma is a complex pathology which represents about 10 % of all hematological neo-plasms. It can often present changes in the hemorheological profile and, in relation to this last topic, our aim is to evaluate the hemorheological profile in a group of multiple myeloma patients, with reference to erythrocyte deformability. Methods: We have examined the profile of the erythrocyte deformability in multiple myeloma enrolling 29 pa-tients; this profile, expressed as elongation index at several shear stress, has been obtained using the diffracto-metric method. Results: By comparing normal controls and MM patients, a significant decrease in erythrocyte deformability, especia…

In-process tool force and rotation variation to control sheet thickness change in friction stir welding of magnesium alloys

2016

Two different in-process control strategies, developed in order to produce sound joints in AZ31 magnesium alloy by Friction Stir Welding on sheet blanks with a non-uniform thickness, are presented and compared. To this purpose, sheets with dip or hump were machined and welded by either changing the rotational speed or the tool plunging in order to keep constant the vertical force occurring during welding. The mechanical strength of the joints was measured in the zones where the sheets before welding were characterised by different thicknesses. The sheets welded by the two different strategies are characterized by very similar ultimate tensile strength values. Finally, the results showed tha…

Design and use of a Fatigue Test Machine in Plane Bending for Composite Specimens and Bonded Joints

2011

Polymeric and composites materials are increasingly used in industry as structural parts, so that specific information on their mechanical properties "at long term" (creep, relaxation, fatigue) are requested. The design and implementation of these components also requires that they are permanently connected together to perform certain functions. The use of adhesives in structural joints has increased over recent years thanks to the continuous development by companies which provide the market with adhesive having better and better mechanical properties. The main areas relate to the aerospace, aeronautical and automotive industries, where requirements are required for lightness and reliabilit…

Study of the Formability of Laminated Lightweight Metallic Materials

2017

The main objective of this work was to test the formability of laminated materials. Laminated materials are considered a good choice when parts with reduced weight are considered. Thus, a laminated material, aluminum - polypropylene - aluminum (Al-PP-Al), as sheet 1.2 mm and 1.4 mm thickness was used. Before processing the material by means of unconventional plastic deformation, its formability was determined by running the Nakajima test. After obtaining the forming limit curves, the material was machined by means of incremental forming.

Influence of some relevant process parameters on the dimensional accuracy in incremental forming: a numerical and experimental investigation

2004

Abstract As known, incremental forming is a flexible and innovative sheet metal forming process which allows complex shape shells forming without the need for any die. For these reasons, incremental forming is nowadays suggested for rapid prototyping and customised products. The present paper is focused on material formability in incremental forming and, in particular, on the evaluation and compensation of elastic springback. The latter significantly modifies the imposed shape. For this purpose, a deeper assessment of the process was developed following three different approaches. First of all, a wide experimental investigation on the influence of some relevant process parameters was develo…

Formability enhancement in incremental forming operations through sheet local heating

2011

Techniques to evaluate erythrocyte deformability in diabetes mellitus

2005

Using several rheological techniques, we examined the erythrocyte deformability in different groups of diabetic subjects. The macrorheological techniques used for this evaluation were respectively whole-blood filtration, filtration of erythrocyte suspensions, polyviscosimetry and diffractometry. Whole-blood filterability, at a negative pressure of 20 cm water, was decreased in type 2 diabetics; no difference was evident at a negative pressure of 10 cm water. The filtration of erythrocyte suspensions at low haematocrit (5%) did not show differences between normal and diabetic subjects. The polyviscosimetry, which explores the filterability of erythrocyte suspensions at high haematocrit (80%)…

Hemorheology in metabolic syndrome

2014

Numerical analysis for formability boundaries definition in sheet metal forming operations

2008

Formability limits in sheet metal forming have been widely investigated through different approaches. The main aim of such approaches was to develop tools able to prevent or predict fracture occurrence in order to improve production quality. Forming limit diagrams (FLDs) and fracture criteria are probably the most utilised tools in this field; nevertheless, some drawbacks of such tools were demonstrated. In particular, forming limit curves are characterised by ineffective prediction capability if non linear deformation paths are taken into account. Moreover, the importance of stress paths was demonstrated in order to predict fracture, and forming limit stress diagrams are, nowadays, deeply …