This module presents the design by calculation developed within the GRISPE project for profiles with perforations arranged in squares. For architectural reasons and also in order to improve the acoustic performance perforated profiles are increasingly developed and used. Different types, geometries and distribution of micro-perforations exist on the profile webs and/or on the flanges. But the European Standard EN 1993-1-3 dealing with design rules for cold-formed members and sheeting covers only profiles with perforations arranged in triangles. Moreover there was a real lack of data and knowledge about the effect of perforations arranged in squares on steel profile resistance and stiffness. Therefore a methodology to design by calculation of profiles with perforations arranged in squares was developed to fill in a lack in design rules. After this introduction of the topic and of the reason why this methodology was developed, this module first describes how this methodology was carried out. It presents the extensive test program of local and global behaviour of steel profiles which was performed in order to provide required data. It gives the results of the analysis of the testing:

• the effect of perforations arranged in squares on local behaviour
• the effect of perforations arranged in squares on global behaviour

It gives also the developed formulas to take into account the perforations arranged in squares in webs or in flanges of a steel profile. Second it explains how to apply these formulas and how to calculate (proposed amendment to CEN TC 250/SC3/WG3 EN 1993-1-3):

• the gross section of a steel profile with perforations arranged in squares in webs or in flanges
• the effective section of a steel profile with perforations arranged in squares in webs or in flanges
• the resistance of a single web with perforations arranged in squares to local transverse forces

Last it introduces four excel sheets which were implemented to calculate span moment resistance, end support reaction and moment-reaction interaction at internal support, for a profile with web perforations arranged in squares and for a profile with flange perforations arranged in squares.  

After the module, you will be able to …

• … remember why some profiles are perforated
• … comprehend why the development of a design by calculation for profiles with perforations arranged in squares was necessary
• … apply the effective thickness for sheeting with perforations arranged in squares as a function of the thickness for sheeting with perforations arranged in triangles
• … analyse the effect of perforations on global behaviour of a profile
• … calculate the effective section properties of profiles with perforations arranged in squares
• … evaluate the resistance of a single web with perforations arranged in squares to local transverse forces

VIDEO – OVERVIEW OF PERFORATED PROFIES

VIDEO – PERFORATED PROFIES

SELFASSESSMENT 

PDF – SLIDES FROM THE VIDEOS