Question

The maximum bending moment at the left quarter point of a simple beam due to crossing of UDL of length shorter than the span in the direction left to right, would occur after the load had just crossed the section by

• A. Three-fourth of its length
• B. Its full length
• C. One-fourth of its length
• D. Half of its length

Answer 1

The correct option is A Three-fourth of its length

Section should divide the load in the same ratio as it divides the span for maximum bending moment.



Length of UDL = a

$\text{Load crossed the section by}\frac{3a}{4}$

$\Rightarrow \frac{wa}{4\times \frac{L}{4}}=\frac{w\times \frac{3}{4}a}{\frac{3L}{4}}$

$\Rightarrow \frac{wa}{L}=\frac{wa}{L}$

So average load on both sides equal.