6. Stresses and Deflection in Helical Springs

Try these first

1. 1.

   What is the wire diameter if tp = 5 mm in a helical spring?

   Hint

   Review the definitions of parameters used in shear stress calculation.

2. 2.

   If the mean coil diameter of a spring is 100 mm, what is its role?

   Hint

   Consider the equation for shear stress.

3. 3.

   The formula for shear stress in helical springs is τ = 8PD/(πd³). What does P represent?

   • Mean coil diameter
   • Axial load
   • Wire diameter

   Hint

   Think about the forces applied to the spring.

4. 4.

   True or False: The number of active coils affects the deflection of a helical spring.

   • True
   • False

   Hint

   Consider how springs work under load.

5. 5.

   A mechanical design requires a helical spring to withstand a maximum load of 600 N with a permissible shear stress of 350 MPa. Using a wire diameter of 8 mm, calculate the mean coil diameter needed to ensure safety.

   Hint

   Don't forget to convert units correctly.

6. 6.

   You have a spring with 15 active coils, 3 mm wire diameter, and you want to calculate how much deflection it will undergo under a load of 200 N, with a shear modulus of 90 GPa. What is the deflection?

   Hint

   Ensure that all measurements are in metric units.