written 6.8 years ago by | modified 2.8 years ago by |
Subject: Structural Analysis 1
Topic: Deflection of Beams using Energy Method
Difficulty: High
written 6.8 years ago by | modified 2.8 years ago by |
Subject: Structural Analysis 1
Topic: Deflection of Beams using Energy Method
Difficulty: High
written 6.8 years ago by | • modified 6.6 years ago |
1.
$\begin{align} & \sum M_A=0 \\& 10\times3+\times4\times\frac{4}{2}-V_D\times4=0 \\& \boxed{V_D=27.5\ kN}\ (\uparrow) \\ \\ &\sum F_Y=0\ (\uparrow+ve) \\& V_A-(10\times4)+27.5=0 \\&\boxed{V_A=12.5\ kN}\ (\uparrow) \\ \\& H_A=-10\ kN \\& \boxed{H_A=10\ kN} \ (\leftarrow) \end{align}$
2.
Region | origin | limit | $M_u$ | $m_u$ | EI |
---|---|---|---|---|---|
AE | A | 0-3 | 10x | 1x | EI |
EB | E | 0-2 | 10(x+3)-10x | (1x+3) | EI |
BC | C | 0-4 | 27.5x-$\frac{10x^2}{2}$ | 1$\times$5 | EI |
CD | D | 0-5 | 0 | 1x | EI |
$ y_D= \int_{0}^{L} \frac{M.m}{EI}\ dx $
$\begin{align} & y_D=\frac{1}{EI}\left[ \int_0^3 (10x)(1x)\ dx+\int_0^2 (10(x+3)-10x)(1x+3)\ dx+\\ \int_0^4 (27.5x-5x^2)(1\times5)\ dx+\int_0^5 (0)(1x)\ dx \right] \\& \phantom{y_D}=\frac{1}{EI}\left[ 90+240+566.66\right] \\& y_D=\frac{896.66}{EI} \dots \left[ E=210\times10^3\ N/mm^2;\ I=2\times10^8\ mm^4 \right] \\& y_D=\frac{896.66}{210\times10^3\times 10^{-3}\times10^6\times2\times10^8\times10^{-2}} \\& \phantom{y_D}=21.34\times10^{-3}\ m \\& \boxed{y_D=21.34\ mm\ (\rightarrow)}\ \underline{Ans.} \end{align}$