Hemming is a three-step sheet-folding process utilized in the production of automotive closures. It has a critical impact on the performance and perceived quality of assembled vehicles. Using a two-dimensional finite element model, this paper presents a design-of-experiments (DOE) study of the relationships between important hemming process parameters and hem quality for aluminium alloy AA 6111...

This paper describes an upper bound analysis of cold forward extrusion of spur gears with modified tooth profile. Spur gear geometrical parameters such as module, number of teeth, pressure angle, bore radius and addendum modification factor were input to a computer program written in Visual Basic. Then spur gear, billet and extrusion die cavity were modeled automatically in SolidWorks. For uppe...

I consider a vesicle with an open pore of small radius rp, exposed to a DNA solution. The crucial moment is the entry, when a chain end faces the pore and enters it. I discuss qualitatively the following three characteristic times: (i) the duration of the entry of one chain end (defining the minimum lifetime of the pore) taue approximately 10(-4) sec, (ii) the transfection time taut (the time r...

Sheet metal forming problems are typical in nature since they involve geometry, boundary and material non-linearity. Cup drawings involves many parameters like punch and die radius, clearance, lubrication, blank holding force and its trajectories etc. So designing the tools for cup drawing involves a lot of trial and error procedure. To reduce number of costly trial error steps, the process can...

Aluminum alloys are considered a lot in the automotive and aerospace industry because of their high strength to weight ratio. In this manuscript, the gas forming process of aluminum AA6063 tubes at high temperatures up to 500°C is investigated, through experimental and numerical tests. Therefore, an experimental setup is prepared and so, tube specimens are formed in a die with square cross sect...

High-pressure torsion (HPT) is a metal processing method in which the sample is subjected to a very high plastic shear deformation. This process can produce exceptional levels of grain refinement, and provides a corresponding improvement in mechanical properties. To investigate the stress and strain distribution due to HPT process finite element simulation were conducted to investigate effectiv...

Effect of retained austenite characteristics on V-bending in ultrahigh-strength TRIP-aided steel sheets with bainitic ferrite matrix (TBF steel) was investigated for automotive applications. tests were performed a servohydraulic testing machine at processing speed 1 mm/min using 88-degree V-punch (2.0 mm punch radius), V-die (12 die gap, 0.8 shoulder and rectangular specimen (50 length, 5 width...

A range of rheological and morphological techniques, contributed by nine laboratories, are used to characterise the flow behaviour in a model long fiber reinforced thermoplastic system. It is concluded that in capillary rheometry, the pressure drop fluctuations that typifl the flow arise from two mechanisms, that of local fiber fraction inhomogeneity passing through the die, and the instability...

A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H i line using the Nançay telescope. All have a Ks-band mean central surface brightness, measured within a 5′′ radius, fainter than 18 mag arcsec and a Ks-band isophotal radius at the 20 mag arcsec level larger than 20′′. We present global H i line parameters for the...