Question

For a cantilever beam of T cross section subjected to uniformly distributed load throughout the length, the maximum bending stress occurs at

• A. mid depth
• B. top of cross section
• C. bottom of cross section
• D. junction of flange and web

Hint:

For any beam section, maximum bending stress always occurs at the extreme fibers (the points farthest from the neutral axis).
For asymmetric sections like a T-beam, you must first determine the location of the neutral axis (centroid) to identify which fiber (top or bottom) is farthest away.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
T-section cantilever with UDL. Where is max bending stress?

Step 2: Key Concept (Alternate):
σ=My/I. Stress proportional to distance from NA. T-section NA closer to flange (wider top).

Step 3: Detailed Explanation:
T-section centroid near flange → y_bottom (web tip) > y_top (flange tip). Hogging moment from UDL causes compression top, tension bottom. Max |σ| = M×y_max/I occurs at bottom fiber where y is largest.

Step 4: Final Answer:
Maximum bending stress occurs at the bottom of the cross-section.