cold roll-forming is a process in which the roll of sheet is formed by passing continuously through the set of rotary rollers without changing thickness in a cool way until it is formed to the desired profile. in this paper a parametric study on the section twist angle in roll-forming the non-symmetric channel is presented, using finite element simulation. at first finite element simulation res...

In this review, a number of recent developments of laser forming are presented based on the work in Manufacturing Research Laboratory (MRL) of Columbia University. In order to advance laser forming to realistic forming application, it is necessary to consider non-straightening and larger scale 3D laser forming, so that anisotropy and size effect need to be investigated in detail. In this paper,...

A crystal plasticity based full-field microstructure simulation approach is used to virtually determine mechanical properties of sheet metals. Microstructural features like the specific grain morphology and the crystallographic texture are taken into account to predict the plastic anisotropy. A special focus is on the determination of the Lankford coefficients and on the yield surface under pla...

In Incremental Sheet Forming (ISF) strains can be obtained well above the Forming Limit Curve (FLC) that is applicable to common sheet forming operations like deep drawing and stretching. This paper presents an overview of mechanisms that have been suggested to explain the enhanced formability. The difference between fracture limit and necking limit in sheet metal forming is discussed. The neck...

After impact onto a smooth dry surface, a drop of viscous liquid initially spreads in the form of a thick lamella. If the drop splashes, it first emits a thin fluid sheet that can ultimately break up into droplets causing the splash. Ambient gas is crucial for creating this thin sheet. The time for sheet ejection, t{ejt}, depends on impact velocity, liquid viscosity, gas pressure, and molecular...

many research studies have been performed on forced convection (active) solar dryers for fruit and vegetables. a short survey of these showed that applying the forced convection solar dryer not only significantly reduced the drying time but also resulted in many improvements in the quality of the dried products. active indirect and mixed-mode thin layer solar drying experiments were conducted o...

A major disadvantage of energy saving glass using tin oxide (SnO2) thin film is that SnO2 attenuates the mobile signal from passing through it. In order to improve such signal transmission, a frequency selective surface (FSS) structures are designed on SnO2 thin film. In this paper, SnO2 thin film with FSS structure was fabricated using combination of printed circuit board technology and reacti...

ultrasonic vibration assisted single point incremental forming (uvaspif) process is an attractive and adaptive method in which a sheet metal is gradually and locally formed by a vibrating hemispherical-head tool. the ultrasonic excitation of forming tool reduces the average of vertical component of forming force and spring-back rate of the formed sample. the spring-back phenomenon is one of the...

Invar36 thin films with various thicknesses from 200 Åto 1400Åare deposited on glass substrates by DC magnetron sputtering technique. After deposition, the samples are annealed in vacuum ambient (10−5mbar) upto 500◦C. Electrical properties of as-deposited as well as annealed films are analyzed with respect to thickness and annealing temperature. In situ measurement of sheet resistance of films ...

Much of the attention on simulation software in recent years has been focused on the modelling of bulk metal forming processes such as forging, rolling and extrusion. However, there are numerous applications for the simulation of sheet forming processes and indeed many pressings suppliers in the automotive industry are more advanced in the use of simulation than their forging counterparts. The ...