I am looking for information regarding the effect of a press fit on fatigue life for a cantilevered round pin subjected to reversed bending load.
The idea involves the application of the superposition. The press fit imposes a compressive stress at the point where the pin emerges from its hole. The reversing transverse load applied to the end of the pin results in alternating tensile and compressive bending stresses at this same section.
Although the compressive stress due to press fit aggrevates the compressive bending stress (additive superposition), the same phenomena reduces the maximum tensile stress in the region immediately adjacent to the section where the pin emerges from its hole. Fatigue being primarily a tensile process the assumption is that the press fit improves the fatige life.
At least this is how I remember the theory from my days at school, quite some time ago. I have been pouring over text books, old class notes, searching the internet etc but can't seem to uncover any sources that discuss this topic. I found some data on cold expansion for improving the life of riveted connections in aircraft. Although related, it's not quite what I am seeking.
Hoping to take advantage of this idea for a design under study, we have been conducting rotating beam fatigue testing on different attachment methods for anchoring pins that will be subjected to reversing bending loads. The results so far, tend to support the idea. But time constraints result in a small sample size. I would like to bolster my confidence in the design with some theoretical backup.
Any suggestions for source materials? Pro or Con.
Jon Juhlin