Fundamental Specifications for Steel Construction/General Provisions

Structural steel is a structural material that has the ability to majorly resists or withstands the forces of tension (as compared to forces of compression that is majorly being resisted by concrete) in a Structure. It is a material that possess high strength, ductility, stiffness, and toughness.

Analysis of cross section
The determination of the strength of a member under a particular limit state shall consider the applicable states of stress within the cross section under the imposed axial, shear, flexural and torsional loadings. The cross section may be analyzed under the combined state of stress or interaction equations may be used to combine member strengths or stress levels as applicable.

Constitutive Relationship (Stress-Strain)
In general, for each limit state considered within the provisions of this specification, the constitutive relationship between element stress and engineering strain shall be assumed to take to form a three part curve with a linear portion up to the yield strain, a perfectly plastic portion from the yield strain to the onset of strain-hardening, and a strain-hardening portion up to the point of ultimate stress or the rupture strain. For limit states not involving rupture, the strain-hardening portion may be neglected to from an elastic-plastic model. For certain flexural limit states involving high strains and for plastic analysis, the elastic and strain-hardening portions may be neglected to form a rigid-plastic model.

Load and load combinations
Member loads, responses, or stresses shall be combined using applicable load combinations from the applicable building code. The selected load combinations shall account for statistical variations in loading and/or incorporate factors of safety in a manner consistent with the design methodology used.

Limit states
The nominal strength of a section shall be limited so that no applicable strength or serviceability limit state shall be exceeded under the applicable load combinations.