Can the beam support a hanging chair?

[Werno]

I have a pergola where I want to hang a sitting hammock from the wooden beam at one short end. The wooden beam is a 45x145 (C24 class) which is attached to 95 mm posts (one at each end). The open span/inner measurement between the posts is 3.2 meters. There is no other load (other than its own weight). Typical fixtures for sitting hammocks consist of an eyelet in a metal piece that is screwed up into the beam from below with one or two screws. Could it be simplified as a point load? The weight of the hammock itself is almost negligible, but the load from an adult needs to be handled. Can the beam manage that?

 

[scorp1on]

Assuming a point load in the middle of the beam equivalent to 150 kg, which is then increased by a factor of 1.35 to get a design load, there are no structural integrity issues for the beam or the columns (moment capacity, shear force, support pressure, and compressive strength with respect to buckling). You get a deflection of 11 mm compared to L/300 = 11 mm.

Then, it might be the case that the attachment fails, perhaps there is a maximum load specified for attachment to wood?

 

[Werno]

Great, thanks! We have a bit of leeway with that weight, so we should be on the safe side. The fittings are special for that kind of suspension, so they should get the job done, I think.