Flanged splice for circular hollow section

[am]

I need to design a splice for circular hollow section; splicing will be with bolted flange connection for axial load coupled with bending moment. I have design guides for axial load only - but not for bending moment. I am looking for some guidance in this matter from any of the forum members. Thank you in advance.

 

[dbuzz]

One option may be to flange the CHS in the same way that pipe spools are flanged and bolted.

A less elegant option would be to slot the CHS into the webs of I-beams and then have a "traditional moment splice on the I-beam stubs.

 

[am]

dbuzz

Thank you for your quick response. I have to go with bolted flange connection. Is there any readily available formula to calculate bolt forces and flange bending moment [based on bolt PCD]? I checked ROARK's hand book but did not find any exact application yet. I will check again. I also checked "Design for hollow structural section connections" by Packer but failed to find any solution to my particular requirement. I will go through both the books again. In the mean time, I am hoping to get some other reference.

Regards

AM

 

[Ron]

Do you have to be concerned about aesthetics? If not, a flange plate with gussets will work. Bolt configuration will be determined by couple to replace moment.

 

[am]

Ron

I can not use gussets. I have to do a long hand calculation to get a satisfactory answer.

Thank you all for your responses.

AM

 

[JStephen]

You might have better luck just approaching this as a piping problem, using regular pipe flanges. Suggest you repost in the mechanical engineering Piping area and see if some of the piping experts there can help.

 

[tgtm]

I once had this same problem and also found no guidance for combined axial/moment flange pipe connections.

My conservative solution - given little time for further research - was to design the entire flanged connection for the maximum tension enduced by the moment + axial load.

 

[Conex]

There is no guidance for this case.

tgtm's conservative solution should be followed, convert moment into an equivalent axial load and add to existing axial load by dividing moment by CHS section modulus then multiplying by CHS area.

 

[StephenA]

You could convert the nett area of the bolts to an equivalent tube on the same PCD. Then you could apply combined bending and tension. That would give you a tensile stress in the bolts, which if applied to all the bolts would give you an equivalent tensile force and then a pressure rating when multiplied by the csa. Then just use the appropriate flange.

StephenA