written 5.2 years ago by |
I. To calculate reaction at support A
$\Sigma \mathrm{Fy}=0$
$\mathrm{R}_{\mathrm{A}}-1-2-3=0$
$\mathrm{R}_{\mathrm{A}}=6 \mathrm{kN}$
II. SF calculation:
$SF at A=+6 \mathrm{kN}$
$\mathrm{C}_{\mathrm{L}}=+6 \mathrm{kN}$
$\mathrm{C}_{\mathrm{R}}=+6-1=5 \mathrm{kN}$
$\mathrm{D}_{\mathrm{L}}=+5 \mathrm{kN}$
$\mathrm{D}_{\mathrm{R}}=+5-2=3 \mathrm{kN}$
$\mathrm{B}_{\mathrm{L}}=+3 \mathrm{kN}$
$\mathrm{B}=+3-3=0(\therefore \mathrm{ok})$
III. BM calculation:
$\begin{aligned} \mathrm{BM} \text { at } \mathrm{B} &=0 \quad \because \mathrm{B} \text { is free end. } \\ \mathrm{D} &=-3 \times 1=-3 \mathrm{kN}-\mathrm{m} \\ \mathrm{C} &=-3 \times 1.5-2 \times 0.5=-5.5 \mathrm{kN}-\mathrm{m} \\ \mathrm{A} &=-3 \times 2.5-2 \times 1.5-1 \times 1=-11.5 \mathrm{kN}-\mathrm{m} \end{aligned}$