ESPcomposites
Aerospace
- Jul 27, 2010
- 692
I am looking for thoughts and opinions about bearing pressure of a pinned joint, in order to develop a better bearing-bypass solution. However, there are some inconsistencies that I am having difficult resolving.
- A cosine distribution seems to underestimate the stress field. This seems to be the standard approach, but seems to be unconservative (used in BJSFM and many other technical papers to simulate bearing pressure).
- Peterson, Chart 4.67, shows bearing Kt factors. This is based on a paper by Frocht and Hill, which is a photoelastic experiment. These results are about 20-30% higher than if one uses a cosine distribution. It seems that Hart-Smith uses this curve and it looks to be used by ESAComp (a high end composite software).
- Most technical papers go from a cosine distribution, then to high fidelity contact analysis. I would be really interested in a paper that attempts to correlate a simple contact analysis with the experimental data in Peterson. I suspect one of the fatigue journals may have something like this?
- I constructed a contact model and it is somewhere in between a cosine distribution and the experimental data, but there are some "odd" things about the results, such as the location of the peak stress. The deformations look appropriate. I can upload a picture if there is any interest.
This is important if one wants to look at joint optimization since the bearing and bypass contributions affect the "optimized" spacing. Johnhors pointed out this thread to me, where a contact solution was then used to create a bearing pressure. But that is for a lug with a hollow pin. I would think that a solid pin with large edge distance would have already been solved?
Hopefully that was not too technical, but any suggestions on papers or where else to look?
Brian
- A cosine distribution seems to underestimate the stress field. This seems to be the standard approach, but seems to be unconservative (used in BJSFM and many other technical papers to simulate bearing pressure).
- Peterson, Chart 4.67, shows bearing Kt factors. This is based on a paper by Frocht and Hill, which is a photoelastic experiment. These results are about 20-30% higher than if one uses a cosine distribution. It seems that Hart-Smith uses this curve and it looks to be used by ESAComp (a high end composite software).
- Most technical papers go from a cosine distribution, then to high fidelity contact analysis. I would be really interested in a paper that attempts to correlate a simple contact analysis with the experimental data in Peterson. I suspect one of the fatigue journals may have something like this?
- I constructed a contact model and it is somewhere in between a cosine distribution and the experimental data, but there are some "odd" things about the results, such as the location of the peak stress. The deformations look appropriate. I can upload a picture if there is any interest.
This is important if one wants to look at joint optimization since the bearing and bypass contributions affect the "optimized" spacing. Johnhors pointed out this thread to me, where a contact solution was then used to create a bearing pressure. But that is for a lug with a hollow pin. I would think that a solid pin with large edge distance would have already been solved?
Hopefully that was not too technical, but any suggestions on papers or where else to look?
Brian
