Problem 1 (5pts)
An overflow valve, shown in sketch below,
has a piston diameter of 15 mm and a slit
length of 5 mm. The spring has mean coil
diameter D = 10 mm and wire diameter d =
2 mm. The valve should open at 1 bar
pressure and be totally open at 3 bar
pressure when the spring is fully
compressed. The shear modulus for the
spring material G = 80 GPa. Spring ends are
squared and ground. Calculate:
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15
1.1. The number of active coils.
1.2. The free length of spring.
1.3. The pitch of the spring.
1.4. Determine the maximum shear stress for this
geometry.