Question

Which of the following is true?

(a) built up column lacings or battens are uneconomical if load carrying members permit greater reduction in weight than what is added by lacing or batten

(b) built up column lacings or battens are economical if load carrying members permit greater reduction in weight than what is added by lacing or batten

(c) no related shear stress force in plane of cross section

(d) built up column designed as axially loaded column can never be eccentrically loaded

I had been asked this question in homework.

The above asked question is from Elastic Buckling of Slender & Built-up Compression Members in chapter Design of Compression Members of Design of Steel Structures

Answer 1

Right choice is (b) built up column lacings or battens are economical if load carrying members permit greater reduction in weight than what is added by lacing or batten

To explain I would say: Built up column lacings or battens are economical if load carrying members permit greater reduction in weight than what is added by lacing or batten. Built up column designed as axially loaded column may be accidentally loaded eccentrically or may have initial crookedness. Variable bending moment will be induced in such column because of eccentricity between centroidal axis of column and line of action of applied load due to this, there will be related shear stress force in plane of cross section and in connecting system.