Ductile fracture prediction of AA6061-T6 in roll forming process

The roll forming is one of the simplest manufacturing processes for meeting the continued needs of various industries. The roll forming is increasingly used in the automotive industry to form High Strength Steel (HSS) and Advanced High Strength Steel (AHSS) for making structural components. In order to reduce the thinning of the sheet product, traditionally the roll forming has been suggested instead of the stamping process. The increased product performance, higher quality, and the lowest cost with other advantages have made roll forming processes suitable to form any shapes in the sheets. In this numerical study, a Finite Element Method is applied to estimate the stress, strain and the thickness distribution in the metal sheet with quadrilateral shape, ribs formed by the 11 steps roll forming processes using a validated model. The metal sheet of size 1,000 × 662 × 1.6 mm taken from SGHS steel was used to form the quadrilateral shape ribs on it by the roll forming process. The simulation results of the 11 step roll forming show that the stress distribution was almost uniform and the strain distribution was concentrated on the ribs. The maximum thinning strain was observed in the order of 15.5 % in the middle rib region possibly due to the least degree of freedom of the material.

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Linear Distribution Principle for Sheet Forming Using Continuous Roll Forming Process

International Journal of Precision Engineering and Manufacturing ◽

10.1007/s12541-019-00292-w ◽

2020 ◽

Vol 21 (4) ◽

pp. 557-564 ◽

Cited By ~ 1

Author(s):

Mi Wang ◽

Guo-long Lu ◽

Zhong-yi Cai ◽

Shu-chen Yang ◽

Ming-zhe Li

Keyword(s):

Sheet Forming ◽

Roll Forming ◽

Forming Process ◽

Linear Distribution ◽

Distribution Principle ◽

Roll Forming Process

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Theoretical Investigation of the Bending Process of the Pre-Strained Metal Sheet

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.299.351 ◽

2020 ◽

Vol 299 ◽

pp. 351-357

Author(s):

Sergey A. Tipalin ◽

Michael A. Petrov ◽

Yuriy A. Morgunov

Keyword(s):

Thin Sheet ◽

Bending Moment ◽

Metal Sheet ◽

Roll Forming ◽

Forming Process ◽

Bending Process ◽

Punch Radius ◽

Zero Radius ◽

Strain Stress ◽

Roll Forming Process

During the bending operation of the thin sheet materials by the punch with the near-to-zero radius the special technological operation should be carried out. It means that the metal sheet obtained a certain thinning value, which is usually done in the form of the channel-concentrator or groove by pre-drawing operation in a cold state. It follows to the pre-straining and strengthening of the material. The authors investigated the strain hardened sheet's area after roll forming process theoretically, and obtained the strain-stress distribution inside the sheet during the bending operation. It was found out that the increase of the prior deformation during pre-straining in the bend layer follows to the increase of the radial and tangential stresses and displacement of the neutral axis inside the blank during bending operation. As a result, the bending moment changes its values depends on the punch radius and strain hardening.

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