WP 1 – MECHANICAL CHARACTERIZATION OF COLD-FORMED STEEL SECTIONS
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 identify and quantify the effects of local plastic deformations due to cold forming process on the properties of the cross sections under cyclic loads.
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 perform 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-analyse 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.
WP 2 – Full scale DETAILS testing AND PARAMETRIC STUDY
WP2 contains the essential part of the research work focused on the assessment of the fatigue resistance of typical cold-formed sections and structural details though experimental and numerical investigations.
Objective 2.1 : to determine the fatigue strength of cold formed steel sections and details by full scale experimental investigations
Objective 2.2 : to generate a database, containing the most relevant information about the test procedure and results
Objective 2.3 : to calibrate the numerical models (both FEM and crack propagation ones) on full scale fatigue test data.
Objective 2.4 : to perform a numerical parametric study of cold-formed steel sections and details subject to fatigue
WP 3 – Categorization of the details and design rules
Based on the investigations carried out at material level (within WP1) and on components and full scale details (within WP2), in WP3 fatigue design rules and recommendations for cold formed steel sections and details adapted to EN 1993-1-9 formulations will be developed and calibrated based on tests results and numerical calculations.
Worked examples will also be produced, in order to provide the users with guidance during the design process.
Objective 3.1 : Categorization of the analysed cold formed steel structural details
Objective 3.2 : Development of a fatigue design model for cold formed steel details to be implemented in the fatigue design methodology of EN 1993-1-9
Objective 3.3 : Development of worked examples.
WP 4 – Project Managment
Objective 4.1: Coordination of the work among different work-packages
Objective 4.2: Organization of the links among the experimental analyses and numerical investigations at the material level (WP1), the full scale experimental investigations (WP2) and design recommendations drafting (WP3)
Objective 4.3: Draft the technical and financial reports to be sent to EU
Objective 4.4: Organization of a final workshop