Offset Element Method on trunions

Posted by: davidorchard

Offset Element Method on trunions - 01/04/11 10:32 AM

I was trying to wrap my head around the Offset Element Method (found in the Applications Guide under Online Documentation) when a thought occurred to me.

Would it be acceptable to use the Near Point Method and offset the connecting node vertically by the amount of the bend radius? This would keep the dummy leg acting along the centerline of the vertical run and place it in the proper place on the bend curvature, but it would be much easier to calculate and input than R(1-cos alpha).

I have tried a couple test models though and the numbers do not come out very similar at all. Am I missing something?
Posted by: Rajinder Singh

Re: Offset Element Method on trunions - 01/06/11 06:00 AM

Using a type of modeling technique depends upon required accuracy of results. If you require accurate result you need to go for Offset Element Method only. I do agree that OEM is bit time consuming but it's worth using when you are dealing with strain sensitive equipments such as turbines.
Posted by: danb

Re: Offset Element Method on trunions - 01/06/11 09:07 AM

The only thing is that using offset you will miss the amount of expansion of the offset length. A rigid without weight used instead of the offset can compensate this.