In WP 1, the influence of the cold-forming process on the fatigue behaviour of steel sections will be studied.

The purpose of this WP is to quantitatively express the effect of local plastic deformations on the cyclic properties of components made of cold formed structural steel.

Objective 1.1 : to study the surface finish conditions of cold formed steel sections and perform a statistical assessment of surface quality levels “on delivery”.

Objective 1.2: to characterize the virgin material

Objective 1.3: to carry out numerical simulations for the study of the local stress concentrations and residual stresses induced by the cold-forming process

Objective 1.4 : to measure the residual stresses due to the cold forming process in typical cross sections

Objective 1.5 : to characterize the material (previously characterized at its virgin state) after cold forming, by means of small-scale tests

Objective 1.6 : to re-analyze the data of fatigue tests on small scale specimens and calibrate models for fatigue crack propagation, also correlating surface finish conditions to the fatigue strength of the details.

Objective 1.7: to identify rules for combining material and production parameters, optimizing the fatigue strength of cold-formed steel sections.