The element d ij if, a flexibility matrix is
- Athe displacement at coordinate j due to a unit force at coordinate i
- Bthe displacement at coordinate i due to a unit force at coordinate jCorrect
- Cthe force at coordinate j due to a unit displacement at coordinate i
- Dthe force at coordinate i due to a unit displacement at coordinate j
Solution
Concept
Meaning of flexibility coefficient
Formula
δ = F P
Step-by-step solution
1. dij is the displacement at coordinate i due to a unit force at coordinate j.
Explanation
Flexibility coefficients relate displacements to forces; the first subscript is where the displacement is measured.
Why the other options are wrong
Options C and D define stiffness coefficients; A reverses the subscripts.
Shortcut
First index = where, second = what unit force.
Common mistake
Reversing i and j.
Correct answer: B) the displacement at coordinate i due to a unit force at coordinate j