Design of Steel Structure (General Engineering) (SSC JE)

Depends upon the carbon content plain carbon steel can be divided into following types–

• Dead carbon steel - upto 0.15% carbon
• Low carbon or mild steel - 0.15 to 0.45% carbon
• Medium carbon steel - 0.45 to 0.8% carbon
• High carbon steel - 0.8 to 1.5% carbon

Column–It is a vertical member which is fixed at both ends and is subjected to an axial compressive load.

Mild steels–The percentage of carbon in these materials range from 0.15% to 0.25%. These are moderately strong and have good weldability.

Medium carbon steel–These contains carbon between 0.3% to 0.8%. The strength of these materials is high but their weldability is comparatively less.

High carbon steel–These contains carbon varying from 0.8 to 8%. These materials get hard and tough by heat treatment and their weldability is poor.

Effective net area–A connection almost always weakness the member affecting its efficiency. The net area determined for plates and flats and other section is modified to account for factors such as ductility of the material, method of fabrication, the geometry factor and the shear lag effect that influence the effectiveness of the member.

All these factors reduce the effectiveness of the member, but shear lag is the most important. The modified net area is called effective net area and may be defined by the following equation

The number 100 in the nomenclature of ISJC 100 indicates total depth of the section.