Search results for "Sheet metal"
showing 10 items of 141 documents
Influence of mechanical properties of the sheet material on formability in single point incremental forming
2004
Abstract New trends in sheet metal forming are rapidly developing and several new forming processes have been proposed to accomplish the goals of flexibility and cost reduction. Among them single point incremental forming operations, in which the final shape of the component is obtained by the relative movement of a simple and small punch with respect to the blank, appear quite promising. In the paper, material formability issues in incremental forming were studied. Some relevant correlations among material formability and other mechanical properties of the material were analysed. The FLD 0 value, i.e. the major strain at fracture in plane strain conditions, was determined for different mat…
Incremental forming of friction stir welded taylored sheets
2006
In the last decade sheet metal forming market has undergone substantial mutations since the development of more efficient strategies in terms of flexibility and cost reduction is strictly due. Such requirements are not consistent with traditional metal stamping processes which are characterized by complex equipment, capital and tooling costs; thus the industrial application of such processes is economically convenient just for large scale productions. For this reason most of the research work developed in the last years has been focused on the development of new sheet forming processes able to achieve the above discussed goals. Contemporary, with particular reference to the automotive indus…
Asymmetric Single Point Incremental Forming of sheet metal
2005
The use of computers in manufacturing has enabled the development of several new sheet metal forming processes, which are based upon older technologies. This paper describes modifications that have been made to traditional forming methods such as conventional spinning and shear forming, forming processes in which deformation is localized. Recent advances have enabled this localized deformation to be accurately controlled and studied. Current developments have been focused on forming asymmetric parts using CNC technology, without the need for costly dies. Asymmetric Incremental Sheet Forming has the potential to revolutionize sheet metal forming, making it accessible to all levels of manufac…
A technical note on an experimental device to measure friction coefficient in sheet metal forming
2006
Abstract In the paper the authors present the results of several experimental tests aimed to determine the Coulomb friction coefficient in sheet metal forming operations at the varying of the sheet metal material and for different operative conditions. In particular a few pressure and lubricating conditions have been investigated. In order to develop such experiments a dedicated fixture was designed and set-up starting from the one proposed by Wilson.
Comparison between aluminum alloys behavior in incremental sheet metal forming process of frustum pyramid shaped parts
2021
Abstract Single point incremental forming is a new emerging technology, used mainly for prototype development or small series production, with good prospects in industrial implementation. However, the parts manufactured through this process often presents low accuracy, thus the industrial implementation is yet limited. Incremental forming process can be done with the help of different technological equipment, such as industrial robots and numerically controlled machines. Since the process is still in development phase, it is a good practice to use finite element analysis software packages in order to reduce time and costs to produce accurate parts. The aim of this paper is to investigate th…
Bond characterization of monolithic and layered glass panels and ultrasonic tests to control glued surfaces
2019
Abstract An experimental investigation is presented regarding the compressive and shear strength of monolithic and PVB laminated glass elements connected by acrylic glue. Ultrasonic tests were also used to control the efficiency of glued surfaces of glass panels. Twenty-four triplets composed of three float glass elements glued with acrylic adhesive were prepared to perform bond tests. Of these twelve triplets were made with monolithic glass elements with a nominal thickness of 20 mm, while twelve were made with layered glass elements 20 mm thick. Three single elements of monolithic glass and three of layered glass were tested for compressive strength. Ultrasonic tests were performed on a s…
Blood flow shapes intravascular pillar geometry in the chick chorioallantoic membrane.
2010
The relative contribution of blood flow to vessel structure remains a fundamental question in biology. To define the influence of intravascular flow fields, we studied tissue islands--here defined as intravascular pillars--in the chick chorioallantoic membrane. Pillars comprised 0.02 to 0.5% of the vascular system in 2-dimensional projection and were predominantly observed at vessel bifurcations. The bifurcation angle was generally inversely related to the length of the pillar (R = -0.47, P .05). 3-dimensional computational flow simulations indicated that the intravascular pillars were located in regions of low shear stress. Both wide-angle and acute-angle models mapped the pillars to regio…
Damping by bulk and shear viscosity for confined acoustic phonons of a spherical virus in water
2007
International audience; A sphere-like virus in water is modeled as a homogeneous isotropic elastic continuum sphere in contact with an infinite viscous compressible Newtonian fluid. The frequencies and damping of the confined vibrational modes of the sphere are calculated for the material parameters of a virus in water. While the effects of viscosity are found to be negligible for a virus-like sphere of macroscopic size, for nanoscale viruses both the frequency and damping of the vibrational modes are significantly affected by the viscosity of the water. Furthermore, both shear viscosity and bulk viscosity play an important role.
Sheet Metal Hydroforming Technology - State-of-the-Art
2016
The present paper describes the current status of hydroforming technology in today’s global market that focuses on energy use in respect to increasing requirements especially from the automotive industry with its renaissance after the economic crisis. A vast hydroforming classification and the restrictions and drawbacks for a wider market share are also presented.
Engineering the hypersonic phononic band gap of hybrid Bragg stacks.
2012
We report on the full control of phononic band diagrams for periodic stacks of alternating layers of poly(methyl methacrylate) and porous silica combining Brillouin light scattering spectroscopy and theoretical calculations. These structures exhibit large and robust on-axis band gaps determined by the longitudinal sound velocities, densities, and spacing ratio. A facile tuning of the gap width is realized at oblique incidence utilizing the vector nature of the elastic wave propagation. Off-axis propagation involves sagittal waves in the individual layers, allowing access to shear moduli at nanoscale. The full theoretical description discerns the most important features of the hypersonic one…