Cold roll forming modifies the mechanical properties of thin walled profiles by strain hardening . The understanding of this phenomenon which is rather good for profiles made of traditional construction steel is mandatory for assessing the member resistance . Less information is however available for profiles made of materials exhibiting a pronounced degree of non linearity of the stress strain curve such as high strength and stainless steels . Current codes generally encounter difficulties for modelling this fabrication process because of the size of industrial mills . Indeed accurate modelling of the continuous cold roll forming process using finite elements requires a huge number of elements leading to excessive CPU times . Therefore modellers usually reduce the geometry of the formed sheet or increase the size of the finite elements inducing a loss of accuracy in the results . In this work the finite element software METAFOR is used to model cold roll forming of channel profiles made of high strength and stainless steels . The numerical results expressed in terms of corner strength enhancement versus radius to thickness ratio are compared against an existing predictive model . Corners total area Cross section area without the corners Gross cross section area Arbitrary Lagrangian Eulerian Central Processing Unit Inter stand distance Young s modulus Finite element model Penalty coefficient Average coil radius Cross section corner radius Cross section internal corner radius Standard deviation Section thickness velocity Strain Equivalent plastic strain Total strain corresponding to 0.2 proof stress Ultimate tensile strain Average Stress Proof stress at 0.2 plastic strain Average yield stress Predicted corner 0.2 proof stress using FEM Predicted corner 0.2 plastic strain using theoretical model Ultimate tensile stress Mill certificate 0.2 proof stress Mill certificate ultimate stress Yield stress Poisson s ratio Cold roll forming and press braking are two common manufacturing processes used for fabricating thin walled structural sections . Roll forming is a continuous bending process during which the thin sheet of metal is successively passed through a set of rolls that incrementally bend it until the desired cross section is obtained . The movement of the sheet through successive combinations of rollers produces the final cross section . During cold rolling the profile undergoes successive states of deformation according to the flower pattern . This process of fabrication implies longitudinal stresses as well as relatively high shear stresses . Consequently the goal of the manufacturer is to find a good combination of successive rollers distance between rollers and speed of rotation to minimise the undesired deformation such as cross sectional distortion or buckling waves in the flats . In press braking a semi manual forming process during which the sheet of metal is bent via a punch onto a die strength enhancement is restricted to corner regions while in roll forming there may also be moderate gain in the flat regions given that longitudinal forces occurring during the forming process may be relatively high and thus lead to plastic straining . The finite element method is regarded by. 


Highlights:
The paper presents a FE model for simulating cold roll forming. Stainless and high strength steels are considered. The corners strength enhancement is reported for each simulation. The numerical predictions are compared with theoretical models.