timber construction - connection details
timber construction - connection details
(OP)
Hi, i have another question.
I attached a picture with a problem.
force in support A is to big for connection with only one steel bolt. So I made wood support nailed to column. is this OK? i have a feeling its not, because there will be some small rotation around that support and vertical force wont apply to the center of this nailed support... What do you think? Any suggestions? In other supports like B,C and D a force is not that large so its not a problem - one steel bolt is OK.
I attached a picture with a problem.
force in support A is to big for connection with only one steel bolt. So I made wood support nailed to column. is this OK? i have a feeling its not, because there will be some small rotation around that support and vertical force wont apply to the center of this nailed support... What do you think? Any suggestions? In other supports like B,C and D a force is not that large so its not a problem - one steel bolt is OK.






RE: timber construction - connection details
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: timber construction - connection details
If I choose 2 or 4 steel bolts in detail A instead of nailed wood support - isnt there a problem with moment? I think i should design steel bolts in this case to vertical load + shear forces because of moment? in case of more then one bolt - what about forces from a moment applied to a column? that might be a problem? or it isnt because its timber and its ductile so there will be rotation/deformation in joint.
RE: timber construction - connection details
Dik
RE: timber construction - connection details
Same answer. I see your point but I, and I believe most other engineers, would not sweat the moment transfer into the column. Obviously, the stiffer your beam is, the less of a problem it's going to be. Also, creep in the connection is going to tend to dissipate your joint moment. Kinda like concrete columns.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: timber construction - connection details
I'm with Koot. All nails or all bolts. Wood is fairly flexible so I wouldn't worry about the moment transfer too much
RE: timber construction - connection details
Dik
RE: timber construction - connection details
RE: timber construction - connection details
Detail A is generally OK but if the wood dries then the whole force will apply to the bolt and beams tend to crack/split.
Don't worry about moments because you don't have a moment connection. You have a shear connection, moment is taken by the beam itself. Rotation is minimal - negligible.
With such forces I would use more bolts OR self tapping screws at an 45 deg. angle.
RE: timber construction - connection details
About wood class C35 and D50 - i know its not common but i couldnt get through with clasic C24. i had limitations about dimensions. I hope its OK.
RE: timber construction - connection details
RE: timber construction - connection details
In my country engineers use C24, C30 and sometimes C35. but when it comes to construction, contractors dont give much damn about it as far as I know. there are also big safety factor for material gamaM = 1,30 and Kmod= 0,9 or less, that brings cca 70% of characteristic value.
RE: timber construction - connection details
So if I change detail A to 2 bolts instead of nailed support i dont have to worry about shear horizontal forces transfered into wood column? If thats the case the only thing i need to do is to control shear capacity of two steel bolts and thats it? Same thing would apply if i use 4 bolts? im adding a picture.
hope you ll answer. tnx.
RE: timber construction - connection details
GL you can get up to GL36 no problem. Hardwood I don't know. Probably nobody grades solid hardwood. Visually yes, but with numbers no. Better to presume lower characteristics in the beggining.
RE: timber construction - connection details
Couldn't you notch the column a bit to interlock with beams? It would certainly be a stiffer connection.
I still can't imagine different wood species for beams and columns.
Good luck
RE: timber construction - connection details