To calculate the Bolt Preload Force:
\[ F = c \times A \times S \]
Where:
Bolt preload refers to the tension force that is applied to a fastener, typically a bolt, when it is tightened. This preload ensures that the working load on the bolt is effectively distributed to the materials it is securing, which helps in achieving optimal performance and safety in the joint. Proper bolt preload is critical to maintaining the integrity and stability of the joint under load.
Example 1: If the constant (c) is 0.75, the tensile shear area (A) is 2.5 in², and the proof load (S) is 3000 lbs:
\[ F = 0.75 \times 2.5 \times 3000 = 5625 \text{ lbs} \]
The Bolt Preload Force is 5625 lbs.
Example 2: If the constant (c) is 0.89, the tensile shear area (A) is 1.8 in², and the proof load (S) is 1500 lbs:
\[ F = 0.89 \times 1.8 \times 1500 = 2403 \text{ lbs} \]
The Bolt Preload Force is 2403 lbs.