I am using spaced wood sections defined by your Leo SPCa.leo. There is one section in the standard United States group and we added several sections to a custom group for our office.
Our sections typically use 4 combined members. The members are typically 2x12's. So, we would have (2)2x12's nailed together with a space of 5.5" and another set of (2)2x12's on the other side. The total width of the beam-column is 11.5". These sections have bending in the major axis and axial stress. I have attached an Output Report for a beam-column that has a total of (2)4x12's and (2)2/12's as one example.
The program has a check box to apply the Repetitive Member Factor Cr in the Wood Design Parameters. The output shows that the member is a repetitive member under the heading "DESIGN CRITERIA", but the section "DESIGN FOR FLEXURE" for M33 shows Cr = 1.00 instead of 1.15. I checked the box to use 1.15. Why is Ram Elements ignoring this factor?
On another note for the same type spaced sections using SPCa.leo, the program will let me set Lu, but the spreadsheet tools will not assign Le. The error message says it only works for rectangular or circular sections. Why?
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Can you send me a zip file of your test model? In my test the Cr factor 1.5 is getting applied using various section types. https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/39895/zipping-a-model
I just uploaded a zip file under a new Service Ticket 7001177006
Thanks, the results are the same for me, so it's not a matter of my version. I'll check with developers to see why that repetitive member setting gets ignored.
Here our findings. The Cr factor (Repetitive Member Factor) applies for dimension lumber 2” to 4”: But this section is 5” thick, so the repetitive member factor should not apply:
In RAM Elements the user has the option to indicate that a member meets the criteria regarding the member spacing (24”), but we are still checking the applicability of Section 4.3.9 regarding the limits of the thickness.
Seth, The reference you provided states that the members must be 2-4" thick and these members may be in contact or spaced no more than 24". Also, there needs to be 3 or more members for this criteria to apply. A beam with (2)2x12's would not meet the criteria, but a beam with (3)2x12's would. This section has 4 members. There are 2 members (1.5"+3.5"=5") in contact, a space and then two more members (1.5"+3.5") in contact.
I did another test file with 1 beam using your S4S Leo to make a beam with (4)2x12's. I got the same result. The member gets marked as a Repetitive member but the Cr = 1.00 instead of Cr = 1.15 in the Wood Design output. Section 4.3.9 and the commentary C4.3.9 both indicate the Repetitive Use factor can be used here.