Hi All,
I have a stress analysis result that doesn't make sense to me. I was wondering if someone could take a look and let me know their opinion.
I have a flat plate, that is loaded with 100psi equally throughout the surface. I have an array of bolt holes that are 120mm x 109mm spacing. When I do the simulation and look at deflection, I see more movement on the ends. I expected the movement to be consistant eveywhere?
Is this an Inventor issue, or are my expectations in error?
On a side bar, is there a better way to constrain holes than on their edges? I would think that would give errors on the stress levels due to the point (line) contact.
If the part being analysed is tapped rather than through-bolted then your first model might be more accurately portraying real life. I was taught that the first 3 threads carry the load so perhaps splitting the hole at 3 thread pitches in and applying the pre-load through that would be the approach. You are going to get high stresses near the fasteners and rapid separation under pressure.
It might be better to build this with a counterbore and the threads nearer the far surface so that the pressure due to pre-loading becomes better distributed.
Richard
@rhinterhoeller wrote:If the part being analysed is tapped rather than through-bolted then your first model might be more accurately portraying real life. I was taught that the first 3 threads carry the load so perhaps splitting the hole at 3 thread pitches in and applying the pre-load through that would be the approach. You are going to get high stresses near the fasteners and rapid separation under pressure.
It might be better to build this with a counterbore and the threads nearer the far surface so that the pressure due to pre-loading becomes better distributed.
Richard
Good Point. I originally designed it with a tapped hole in one plate, since the initial FEA, I am now leaning to through holes with nuts and washers.
bhowe,
FYI: I am just throwing this info out there for you to be aware of. Don't take it personal, it may not apply to you at all. I commend your tenacity to grind through this FEA problem. I don't know what laws apply in your area but in California, in most cases only state licensed Engineers can legally provide Engineering services. As a licensed Engineer I know the time and effort involved to obtain that license and get flustered when non-Engineering people provide Engineering services.