problem 1a steel simple beam ab is supported by a

Question

Problem 1:

A steel simple beam AB is supported by a copper wire at the middle point C. The beam is subjected to a pair of concentrated force P = 4 KN (see figure)

steel beam AB: Lenght L = 4m with a fretangular cross section of height 20 cm x width 10 cm.

copper wire BD: lenght h = 1m with a circular cross section of diameter d = 5 mm.

Steel Es = 200 GPa; copper Ec = 100 GPa

Is this system determinate or indeterminate?

Determine the deflection δ_c of the beam at the end B.

Problem 2:

A rigid bar (ignore its weight) hangs from flute equally spaced vertical wires (length L = 150 mm, spacing a = 50mm): two the steel and one of aluminum. The wires also support a load P acting on the bar. the diameter of the steel wires is d_a = 4 mm. Assume Es = 210 GPa and Ea = 70 GPa.

What load P_allow can be supported at the midpoint of the bar if the yield stress in the steel wires is 220 MPa and in the aluminium wire is 80 MPa? A saftey factor of n = 2 is needed.