Solution:

Step 1: Draw the stress-strain curve of low-carbon structural steel

The figure shows a typical stress-strain curve of a ductile structural steel and it can be assumed same for both the cases of tensile and compressive load.

Step 2: List the three regions of the stress-strain curve.

The three regions of stress-strain diagram of mild or low carbon structural steel are:

• Elastic strain region
• Plastic strain region
• Strain Hardening region

Step 3: Discuss the terms of these three regions.

Elastic strain region:

• Within this region the stress linearly varies with strain
• Hook’s law applies to this region.
• Within this region any material receives largest stress without permanent deformation

Plastic strain region:

• Within this region the the stress doesn’t vary linearly with strain.
• In this region strain considerably increases without further increase in stress.
• Plastic strain is around 10 to 15 times more than elastic strain.

Strain Hardening region:

• In this region a further increase in stress is required to produce strain
• This region is not so important for designers.

End of Solution