
Re: Stress analysis on Bracket
Mikael Martinsson May 11, 2012 7:57 AM (in response to Vijayendra Srinivasa Rao)Hi.
A picture of the problem would of course be nice to understand it better. (dimension of the bolts, bolt direction and distances compared to the COGload to understand axial, shear and bending moments).
My knowledge is poor on how to properly use the safety factor and the "safety check plot" with bolt connectors in SW Simulation. Since you normally preload the bolts, lets say up to 7590% of its proof load strength it is kind of hard to reach a FOS of 2 or 3 on each bolt. Especially if you use yield limit as "bolt strength" and have other loads that imposes shear, bending moment or additional axial loading to the bolt. I always set FOS = 1 as the limit for each bolt in the "strength data" section and then look at the combined FOS for the bolt pattern. Hand calculation is also a good idea.

Re: Stress analysis on Bracket
Vijayendra Srinivasa Rao May 14, 2012 9:35 AM (in response to Mikael Martinsson)Hello Mikael,
Thanks for your reply. Now I have uploaded the image which I am doing some analysis.
As you mentioned some point in the above, I have calculated the Torque preload condition manually (which is 4.5Nm) and applied on each bolts. Also I have used the Yield strength as the strength of the fastener Assy.
During the simulation I have defined the FOS of 1.5. The combined Fos on each bolt is greater than 1.5 and I have verified with hand calculation as well.
When I define a Fos of 2 o each bolt, the result shows less than Fos 2. I was confused about this result. Can you please give some information regarding this result?
Also, can't we do the analysis by defining higher Fos on each Bolt, because the strength of the 1/420 Hexagonal Headed bolt with A2 ST/ST has to withstand higher load.
Thanks
Vijay
