Question

A member ABCD is subjected to point loads P1,P2,P3, and P4 calculate the force P3 necessary for equilibrium if P1, = 120 kN, P2, = 220 kN and P4, = 160 kN. Determine also the. net change in the length of the member. Take E = 200 GN/m²

Answer 1

$\sum P=0$

$P_1+P_2+P_3+P_4=0$

120+220+160+P₃=0

P₃=-500kN

$∆l=\frac{\sigma l}{E}$

=$\frac{500000*25}{25*15*200*10^9}$

=1.6667*10^-7