BAsic doubt-1D element
BAsic doubt-1D element
(OP)
1)How do i get the stiffness matrix of a 3 node one dimensional quadratic element( i have problem in integration).do i have to express the coordinate of interior node in terms of end nodes( non dimensionalize)
2)Can a combination of such elements be assembled to form a bigger one dimensional element. is the ususal assembly procedure valid. can i have 2- 3 noded id elements combined to form a structure with 5 nodes
please help me
2)Can a combination of such elements be assembled to form a bigger one dimensional element. is the ususal assembly procedure valid. can i have 2- 3 noded id elements combined to form a structure with 5 nodes
please help me
Raj





RE: BAsic doubt-1D element
A) If I didn't make a mistake, the matrix is:
[ 7 -8 1]
|-8 16 -8|
[ 1 -8 7]
Multiplied by AE/8L
B) I can't think why the usual assembly procedure woudn't hold.
The easiest way to find out is assembly it and compare your matrix answers with hand calcs for a variety of displacements vectors for which you can obtain a solution.
Brad
RE: BAsic doubt-1D element
:)
RE: BAsic doubt-1D element
shouldnt it have a square term of length.......u being quadratic
Raj
RE: BAsic doubt-1D element
Raj
RE: BAsic doubt-1D element
Been on the road.
As defined, L is the total length (for my example, L is the length between node 1 and 3, with node 2 seated exactly in the middle).
I don't think that L is squared (there were 2nd order variables in the derivation, but they fall out).
The units as I described fall into place properly; hence I'm pretty sure that I didn't make a mistake (but please verify).
Brad
RE: BAsic doubt-1D element
Raj