Question

The ratio of distribution factors of member BA and CD in the frame shown below is

• A. 1.369
• B. 0.98
• C. 1.217
• D. 0.822

Answer 1

The correct option is C 1.217

Joint	Member	k	$\Sigma k$	Deflection factor
	BA	$\frac{8EI}{5}$		$\frac{8}{23}$
B	BE	$\frac{4EI}{4}$	$\frac{23EI}{5}$	$\frac{5}{23}$
	BC	$\frac{8EI}{4}$		$\frac{10}{23}$
	CB	$\frac{8EI}{4}$		$\frac{10}{21}$
C	CF	$\frac{4EI}{4}$	$\frac{21EI}{5}$	$\frac{5}{21}$
	CD	$\frac{6EI}{5}$		$\frac{6}{21}$

$\therefore \frac{{\left(DF\right)}_{BA}}{{\left(DF\right)}_{CD}}=\frac{8/23}{6/21}=1.217$