A sluice gate $($gate to open and close the flow of water$)$ is raised

and lowered by means of a square threaded screw as shown in

the figure. The weight $"w"$ of the gate is $2$ kN $.$ The normal

force $"F"$ on the gate due to the pressure of the water is $6$ kN $.$

The gate slides in the channel having a coefficient of friction

of $0\mathrm{.}3.$ Following are the knowns:

Major diameter of the screw $=30mm$

Pitch of the screw $=8mm$

Collar diameter $($thrust collar$)=80mm$

Coefficient of friction for both screw and collar $=0\mathrm{.}1$

Hand wheel diameter $=300mm$

Calculate:

a$)$ The force

on the Hand wheel required to rise

the gate by rotating the wheel

b$)$ The normal, bending and torsional stresses $($in MPa$)$ in

the screw

c$)$ the von Mises stress, and

d$)$ the factor of safety. The yield strength is $250$ MPa

Hand Wheel