Hi, you lost me a little when you were compartmentalising the global matrix before the final calculations. How do I know where to split the matrix? Thank for your helpful videos!
Sir, great video. really helpful. after years of your posting this video, can you tell me how to apply 2D floor slab as a diaphragm over 1D frame structure and calculate the stiffness matrix? Thanks again.
I think the value of u1-v1 in the global stiffness must be zero since the formula related to it must be multiplied by cos and sin, but since the theta is 90, cos must be zero, resulting to zero value of u1-v1?
Hi, Thanks for the comment. If I understand correctly, and please correct my if I'm wrong, the value you are referring to in the global matrix is 4.27E-8, which is very close to and, for all tends and purposes, zero when relating to the actual stiffness values, all > 10k,. I suspect the nonzero value has its origins in rounding errors or something of that nature. I hope this gives some clarity.
How can you set up a spreadsheet so that the support conditions of the frame can be varied and excel can automatically calculate the reactions you require?
+Esraa Haraz Thanks for the comment. I don't think that is possible. As the constant EI is one of the assumptions made at the start of the development of the matrix. I think for a variable EI in the same element a new element matrix will need to be derived to accommodate this. I hope this answers your question.
+TM'sChannel Thanks for replying and sorry for bothering you drive.google.com/file/d/0B_f62jgFY5pSX3BNMURxNzBJODA/view?pref=2&pli=1 something like that i want to solve it as three elements not five , what should i do ?i thanks in advance .
Hi, I think for that element configuration, 5 elements is the best way to go. Seeing as I don't have the element matrix for an element with variable stiffness. But if you manage to locate (or derive) one, please let me know. Regards
Naeema Ismail Hi. Thank you for the comment. I'm not sure I understand your question. In the above example EI is given as constant for the problem. For any value of E or I, it will just have an effect on the element stiffness matrix. The procedure will still be the same, just with different element matrices. Sorry if this reply wasn't much help :)
