Question

What is the moment at A for a frame as shown in figure below ?



Each members indicated in dark lines has very large moment of interia.

• A. $\frac{PL}{2}$
• B. $\frac{PL}{4}$
• C. $\frac{PL}{8}$
• D. $\frac{PL}{16}$

Answer 1

The correct option is B $\frac{PL}{4}$





Compatibility condition

${\Delta }_E={\Delta }_A$

$\frac{R(2L{)}^3}{48EI}=\frac{(P-R)(2L{)}^3}{48EI}$

$R=\frac{P}{2}$

$\sum V=0$

$2R_1=\frac{P}{2}:R_1=\frac{P}{4}$

$M_A=\frac{PL}{4}$