medeek
Structural
- Mar 16, 2013
- 1,104
Let's assume I've got a larger garage door header (16' span) that is dropped down from the ceiling about 5', on the gable end of the garage. It's going to pick up certain amount of dead load and snow load from the roof, not much but some. If one were to simply look at the vertical loads the header size could be quite small, maybe a 4x12 DF No. 2 would be typical.
Now if I add in a C&C wind load that is perpendicular to the wall and assign some of the load to this header via the pony wall above it I have a beam that is loaded in biaxial bending.
I typically use Forte for a lot of my quick beam and header calcs but it does not let one apply a out-of-plane load to a glulam header. I am wondering if anyone has any suggestions for a different app/program that can calculate biaxial bending in glulam beams and headers. I contacted Woodworks and their sizer program also does not do biaxial bending or loads.
On that same note I was thinking about writing my own spreadsheet/program that will do the calculations but then it occurred to me that I don't actually know what equation to use for pure biaxial bending (no compression or tension axial loads combined). Do I use equation 3.9-3 with the first term disappearing or would it be more appropriate to use equation C3.9.2-1 with its first term disappearing? Notice the slightly different result since the first option would include fbx/FbE in the second term.
Would the Fbe term be computed with E'y min or E'x min?
A confused student is a good student.
Nathaniel P. Wilkerson, PE
Now if I add in a C&C wind load that is perpendicular to the wall and assign some of the load to this header via the pony wall above it I have a beam that is loaded in biaxial bending.
I typically use Forte for a lot of my quick beam and header calcs but it does not let one apply a out-of-plane load to a glulam header. I am wondering if anyone has any suggestions for a different app/program that can calculate biaxial bending in glulam beams and headers. I contacted Woodworks and their sizer program also does not do biaxial bending or loads.
On that same note I was thinking about writing my own spreadsheet/program that will do the calculations but then it occurred to me that I don't actually know what equation to use for pure biaxial bending (no compression or tension axial loads combined). Do I use equation 3.9-3 with the first term disappearing or would it be more appropriate to use equation C3.9.2-1 with its first term disappearing? Notice the slightly different result since the first option would include fbx/FbE in the second term.
Would the Fbe term be computed with E'y min or E'x min?
A confused student is a good student.
Nathaniel P. Wilkerson, PE
