Question

In a steel plate with bolted connection, the rupture of the net section is a mode of failure under

• A. Tension
• B. Compression
• C. Flexure
• D. Shear

Hint:

For steel tension members, remember the three important failure modes:
• Gross section yielding
• Net section rupture
• Block shear failure Net section rupture always occurs under tensile loading.

Answer 1

The Correct Option is A

Concept: In a bolted tension member, bolt holes reduce the effective cross-sectional area of the plate. The portion remaining after deducting the bolt holes is called the net section. When the tensile force exceeds the tensile capacity of the net section, rupture occurs. According to IS 800:2007, the major modes of failure of a tension member are:
• Yielding of the gross section.
• Rupture of the net section.
• Block shear failure.

Step 1: Understand the net section failure. The tensile force acts along the length of the member. Because bolt holes reduce the effective area, \[ A_n<A_g, \] where \[ A_n=\text{Net sectional area},\qquad A_g=\text{Gross sectional area}. \]

Step 2: Identify the mode of failure. When the tensile stress in the net section exceeds the ultimate tensile strength, \[ \sigma_t=\frac{P}{A_n}, \] the plate ruptures across the net section. Hence, \[ \boxed{\text{Rupture of the net section is a tensile failure.}} \] Therefore, the correct option is \[ \boxed{(A)\;\text{Tension}.} \]