taper stud / hole strength

[netzen]

I ran into a problem that need to use a 1:10 taper stud / bore connection to transfer loads, the smaller end of the taper is ~1.0" and the entire engage length is 1.125".

The stud is conical shaped and made out of hardened steel and material (cast iron, grade, etc.) on the female part is yet TBD. Very typical configuration if you've seen a tie rod assembly used a lot on automotives

could someone recommend a calculation method to estimate the joint fatigue capacity based on a certain loading?

I've originally posted this under Structural Engineering forum then was told more help might be available from this forum.

Thx a lot!

 

[cntw1953]

netzen:

Based on my limited knowledge, fatigue strength of bolted connection is affected by many factors, such as type of jointed materials, load range and cycles. Please have a look on linked site, it might lead you to where you wanna to. Good luck.

http://findarticles.com/p/articles/mi_qa5357/is_200411/ai_n21359024/

 

[netzen]

thanks a lot cntw1953!

It just seems there ought to be some sort of empirical/theorethical way to estimate the joint behavior.

Best regards!

 

[cntw1953]

Try automotive forum if this is some setup usually seem in that field. Good luck, and let me know if you are able to find something on it.

 

[unclesyd]

I can't help very much on your calculations by will offer a word of advice bases on some fatigue failures.
We used a lot of rented transport trucks to move material from primary to secondary operations. Because these trucks were used in tight quarters that required a lot of tight turns there was exceptional wear on the front tires. To alleviate this the rental company installed an after market part to improve the turn radius. The device worked well for several months until one of our rental trucks made a 90 degree turn into gas station taking out a gas pump. Our group was called in as there was reports that the king pin had crystallized. Our investigation quickly revealed that the failure was a fatigue failure. The offending part was removed from one our rental trucks in for a service and it was evident that it had started to crack. Plant management quickly grounded our rental fleet. One driver decided not to heed the max speed waring on his return trip and his pin broke and he plowed up a field of flowers. We found cracks on all our rental vehicles and 2 in rental companies parked inventroy. The problem originated from the after market product didn't match the taper on the vehicle. It essentially ended up with only the top 1/3 of the pin carrying the load.

Also I've never seen any calculations that matched actual condition in CI when it come to fatigue.