Pins Design
Pin #1
In the riveter the two pins that must be used are design to have the same dimensions, we will focus on the pin with most stress concentration, in this case will be the pin pulling the mandrel to break the rivet. If we design this pin strong enough to handle the forces done by the riveter, then the other pin in which has less stress, will be strong enough to handle the forces at the pivot point
Free Body Diagram
The maximum force that will applied to the pin will be 1400 lbf which will be distributed to 700 lb./0.1 in , which is the width of the material that comes from the handle.
Shear/Moment Diagram
Based on the moment diagram the two main point to be analyzed are point B which is at the maximum moment just after the maximum shear, the other point is just before C. We will focus on point B in the Stress Analysis section.
Stress analysis
Focusing on point B the primary force we will experience will be shear, since the handle will be pulling the mandrel up and the mandrel will be resisting the force down.
To make sure the stress we consider is the highest we also consider bending stress and transverse shear, just to be safe.
By calculating different stresses, the maximum stress will be the maximum shear. Then we can move forward calculation our von mises and principal stresses.
The first stress we will consider at point B will be maximum shear Stress at this point
Principal stresses and Von Mises stress
Considering our principal stresses, we move forward in considering our factor of safety. We must choose a material in order to find a factor of safety. Most pins are made of Zinc-Platted Carbon Steel which in our case we choose AISI 1045
Our factor of safety turned out to be 3.1 for this pin.
Fatigue analysis
Using fatigue criteria, the pin turned out to have infinite life
Chosen Pin
PIN #2
Free Body /Shear/Moment Diagram
Stress analysis
Focusing on point B the primary force we will experience will be shear, since the handle will be pulling the mandrel up and the mandrel will be resisting the force down.
The first stress we will consider at point B will be maximum shear Stress at this point.
To make sure the stress we consider is the highest we also consider bending stress and transverse shear, just to be safe.
By calculating different stresses, the maximum stress will be the maximum shear. Then we can move forward calculation our von mises and principal stresses.
Principal stresses and Von Mises stress
Considering our principal stresses, we move forward in considering our factor of safety. We must choose a material in order to find a factor of safety. Most pins are made of Zinc-Platted Carbon Steel which in our case we choose AISI 1045
Our factor of safety turned out to be 2.89 for this pin.
Fatigue analysis
Using fatigue criteria, the pin turned out to have infinite life
Chosen Pin
For Pin #2 there will not be similar as the first pin, it will be welded at the ends. It could be made by using an AISI1045 rod or a similar pin can be purchased from Mcmaster-Carr made out of AISI1144 . This material when compared to AISI 1045 will be stronger and same calculations can be performed.
