StreakPeaked· Practice

ExamsGATETechnical

When a simply supported elastic beam of span $L$ and flexural rigidity $EI$ (where $E$ is the modulus of elasticity and $I$ is the moment of inertia of the section) is loaded with a uniformly distributed load $w$ per unit length, the deflection at the mid-span is $\Delta_0 = \frac{5wL^4}{384EI}$. If the load on one half of the span is now removed, the mid-span deflection ________.

  1. reduces to $\Delta_0/2$
  2. reduces to a value less than $\Delta_0/2$
  3. reduces to a value greater than $\Delta_0/2$
  4. remains unchanged at $\Delta_0$

Correct answer: reduces to a value greater than $\Delta_0/2$

Solution

The original deflection is due to UDL over the entire span. If the load on one half is removed, the mid-span deflection decreases, but not by half of $\Delta_0$ because the load distribution is no longer symmetric. By superposition, the reduction is less than the contribution of half the full-span load at the center, so the new deflection is greater than $\Delta_0/2$.

Related GATE Technical questions

⚔️ Practice GATE Technical free + battle 1v1 →