Dec 2014, AutoPIPE V8i 09.06.01.10
How to model a U-bolt (ubolt) in AutoPIPE? If the U-bolts are clamped tight can anyone tell me the proper way to model these supports? What friction factor should I use?
This has already been answered on the AutoPIPE forum by Karim Rinawi:
http://communities.bentley.com/products/pipe_stress_analysis/f/275801/t/80802.aspx
and copied below for convenience:
A U-bolt can be modeled as:
a. A guide support type
b. Combination of 2 or more incline type supports at the same node point
An industry accepted friction factor value between 0.3 to 0.4 is commonly used for metal to metal contact at support locations unless low friction pads are added in which case 0.1 can be used (recommend contacting manufacture for actual friction coeff.).
If the U-bolt is tight, then a non-metallic padding is usually added, otherwise the pipe will dent due to hoop radial expansion or the support will break due to axial growth. Most of the friction will come from horizontal surface where the weight is acting and so the above mentioned factors should be used. If the tightness is excessive, it can be expressed as an equivalent normal radial force (contact pressure*contact area) and that can be used to evaluate the friction factor by dividing the force by the gravity reaction.
Beam Structure modeling
Bentley AutoPIPE