Explanation: Net area = Gross area – deductions, that is net area of tensile members is calculated by deducting areal of holes from the gross area.

Explanation: When every fibre of the section has a strain equal to or greater than εy=fy/Es , nominal moment strength is referred as plastic moment and is given by Mp = Zpfy , where Zp = ∫ydA is plastic section modulus and fy = yield stress.

Explanation: (i) There is little saving in column design, (ii) lateral bracing requirements are more stringent than for elastic design, (iii) difficult to design for fatigue,(iv) moments produced by different loading conditions needs to be calculated separately(cannot be added together) and the largest plastic moment is selected.

Explanation: Plastic hinges normally occur at supports, points of concentrated load, and points where cross section change. The location of plastic hinge in a beam with uniformly distributed load is not well defined.

Explanation: When equilibrium and plasticity conditions of plastic analysis are satisfied, an lower bound solution of true ultimate load is obtained.

Explanation: Load factor is ratio of collapse load to working load. It is represented by, F = Wc / W.

Explanation: Cross section are classified into four behavioural groups depending upon the material yield strength, width-to-thickness ratio of individual components (e.g. webs and flanges) within the cross section, and the loading arrangement.

Explanation: In torsional buckling, failure occurs by twisting about shear centre in longitudinal axis. It occurs when torsional rigidity of member is appreciably smaller than bending rigidity. It can occur only with doubly symmetric cross section with very slender cross sectional elements. Standard hot rolled shapes are not susceptible to torsional buckling.

Explanation: If the net end moments are not zero, the member will be subjected to axial force and bending moments along its length. Such members are called beam-columns.

Explanation: Axial loading on columns in buildings is due to loads from roofs, floors, and walls transmitted to the column through beams and also due to its own self weight.

Explanation: The decrease in strength of slender member is due to following parameter : imperfections- initial lack of straightness, accidental eccentricities of loading, residual stress, and variation of material properties over the cross section.

Explanation: Strut, boom and rafter are compression members, whereas tie is a tension member.

Explanation: The value of the imperfection factor, α for buckling class a is 0.21. The imperfection factor considers all the relevant defects in real structure when considering buckling, geometric imperfections, the eccentricity of applied loads, and residual stresses.