Design templates – a new tool for computer-aided design of structural elements

A design template is defined as a scheme of computer-aided design process which could be verified and modified in particular cases by a designer. Global loads have to be determined and analysis is performed for each arrangement of unit loads separately. Thus, the influence matrices are determined and also: matrix of interaction of load effects and matrix of combination of simultaneous loads. New matrix procedures are introduced in order to identify the most unfavourable load arrangements and then – the most unfavourable load combinations and load effect interactions. The design templates are exemplified for portal steel frames subject to permanent loads, variable actions and second-order horizontal forces due to sway of the columns. Complex influence coefficients are introduced and amplified sway of the frame is taken into consideration. Corrections of some unsound clauses of the Eurocodes l and 3 are suggested.