What is the Difference Between Tension and Compression Members with regarding to Structural Engineering? | Q & A

In civil engineering structures, members are classified based on the type of internal force they primarily resist.

1. Tension Members What Are They?

Tension members are structural elements that resist pulling forces (tensile stress).

Examples:

• Bottom reinforcement in beams

• Tie rods

• Suspension bridge cables

• Bracing members

• Steel ties

Key Characteristics:

• Subjected to elongation

• Failure is usually sudden if not designed properly

• Steel reinforcement plays the main role

• Concrete alone is weak in tension

2. Compression Members What Are They?

Compression members resist pushing forces (compressive stress).

Examples:

• Columns

• Struts

• Compression zone of beams

• Load-bearing walls

• Piers

Key Characteristics:

• Subjected to shortening

• Failure can occur by crushing or buckling

• Concrete is strong in compression

• Steel is used to resist buckling and add strength

3. Tabular Comparison (Best for Interviews)

  Tension          MemberCompression Member Aspect

4. Site-Oriented Explanation

In beams, top concrete is in compression and bottom steel is in tension.

5. One-Line Interview Answer (Perfect)

Tension members resist pulling forces, while compression members resist pushing forces in a structure.

Common Follow-Up Interview Questions

Q: Why is steel provided in compression members if concrete is strong in compression?
A: To resist buckling, increase load capacity, and improve ductility.

Q: Which member is more critical in failure?
A: Tension members, because they fail suddenly without warning.