Calculate riveting force, required rivet count, and joint capacity from rivet strength, area, load, diameter, and safety factor values.
Riveting Force Formula
The following equation estimates shear load capacity, not the force needed to install or form a rivet.
- Where RF is the single-plane shear load capacity (lbf)
- SS is the shear strength of the rivet (lbf/in^2)
- A is the cross-sectional area (in^2)
To calculate the riveting strength, multiply the shear strength of the rivet by the total area of the shear.
What is a Riveting Force?
Definition:
Here, riveting force refers to estimated shear load capacity. Actual joint capacity also depends on bearing, tear-out, net section, load distribution and other failure modes. It is not an installation-force calculation.
How to Calculate Riveting Force?
Example Problem:
The following example outlines the steps and information needed to calculate the Riveting Force.
First, determine the shear strength of the rivet. In this example, the shear strength of the rivet is found to be 500 lbf/in².
Next, determine the cross-sectional area. For this problem, the area is found to be 3 in^2.
Finally, calculate the Riveting Force using the formula above:
RF = SS*A
RF = 500*3
RF = 1500 lbf
FAQ
What factors can affect the shear strength of a rivet?
The shear strength of a rivet can be affected by several factors including the material of the rivet, the diameter of the rivet, the temperature at which the rivet is used, and the presence of any manufacturing defects. Different materials have different inherent shear strengths, and larger diameters generally provide greater shear load capacity because they increase cross-sectional area; they do not inherently increase the material’s shear stress strength. Additionally, extreme temperatures can weaken the rivet, reducing its shear strength.
How do you determine the appropriate cross-sectional area for a riveting application?
The appropriate cross-sectional area for a riveting application depends on the forces that the joint will experience in service. Engineers must consider the maximum load the joint will bear and select a rivet size and material that can withstand the load without failure. The cross-sectional area is then calculated based on the diameter of the rivet. Safety factors are often applied to ensure reliability under unexpected conditions.
Can the riveting force formula be used for all types of rivets?
While the basic principle of the riveting force formula (RF = SS*A) applies broadly, adjustments may be needed for specific types of rivets or applications. For example, blind rivets, which are used when only one side of the joint is accessible, may require consideration of additional factors such as grip length. Similarly, for rivets subjected to double shear, the calculation might be adjusted to account for the increased load-bearing capacity. It’s important to consult technical resources or engineering guidelines specific to the type of rivet and application.
