Question

Which of the following statement is correct?

(a) Internal elements are elements attached along both longitudinal edges to other elements

(b) Outstanding elements are elements attached along both longitudinal edges to other elements

(c) Outstanding elements are elements which are free along both the edges

(d) Internal elements are elements which are free along both the edges

I had been asked this question in quiz.

My doubt is from Cross Sectional Classification topic in section Plastic and Local Buckling Behaviour of Steel of Design of Steel Structures

Answer 1

Correct option is (a) Internal elements are elements attached along both longitudinal edges to other elements

For explanation I would say: Internal elements are elements attached along both longitudinal edges to other elements or to longitudinal stiffeners connected at suitable intervals to transverse stiffeners connected at suitable intervals to  transverse stiffeners (e.g. web of I-sections and flange and web of box sections). Outstanding elements are attached along only one of the longitudinal edges to an adjacent element, the other edge being free to displace out of plan (e.g. flange overhang of an I-section, stem of T-section, leg of angle section).