Hi,
I am trying to export elemental stiffness matrix from Abaqus by adding the following lines in the input file "*Element Matrix Output, Elset=Set-1, File Name=myMatrix, Frequency=1, Output File=User Defined, Stiffness=Yes" for 4-noded linear quad element. I got stiffness matrix but the size of this matrix is 12x4 while it should be 8x8. Could you please explain how the Abaqus is writing the elemental stiffness matrix? Please check attached output for your reference.
Hi, You have been provided with the symmetric part of the 8X8 stiffness matrix K (36 values including diagonal terms). The layout is as follows
K11,
K12,K22,
K13,K23,K33,
K14,K24,K34,K44,
K15,K25,K35,K45,
K55,
K16,K26,K36,K46,
K56,K66,
K17,K27,K37,K47,
K57,K67,K77,
K18,K28,K38,K48,
K58,K68,K78,K88
To get the full stiffness matrix, insert the following lines into *.inp file:
*STEP, NAME=export matrix
*MATRIX GENERATE, STIFFNESS
*MATRIX OUTPUT, STIFFNESS, FORMAT= COORDINATE
*END STEP
The full stiffness matrix will be in the *.mtx file.
Ram Kumar You might be interested in
https://docs.scipy.org/doc/scipy/reference/generated/scipy.io.mmread.html
https://docs.scipy.org/doc/scipy/reference/generated/scipy.io.savemat.html
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