


REDUCEMATRIXSTOKES - compute a reduced matrix to get rid of the bubble grid
This function return the reduced elementary matrix, so that we ca
solve the problem without having a grid in the middle of the pentaelem
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Ke_temp=[ Kii | Kib]
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[----------------+----]
[ Kbi | Kbb]
indice b represents the bubble function (node in the middle of the penta
indice i represents the other nodes (the six principal nodes of the penta)
So that the elementary reduced matrix is Ke_reduced=Kii-Kib*Kbb^-1*Kbi
See theoryguide for more informations
Usage:
Ke_reduced=ReduceMatrixStokes(pentaelem,Ke_temp)
See also REDUCEVECTORSTOKES, CREATEKMATRIX

0001 function Ke_reduced=ReduceMatrixStokes(pentaelem,Ke_temp) 0002 %REDUCEMATRIXSTOKES - compute a reduced matrix to get rid of the bubble grid 0003 % 0004 % This function return the reduced elementary matrix, so that we ca 0005 % solve the problem without having a grid in the middle of the pentaelem 0006 % [ | ] 0007 % [ | ] 0008 % Ke_temp=[ Kii | Kib] 0009 % [ | ] 0010 % [----------------+----] 0011 % [ Kbi | Kbb] 0012 % indice b represents the bubble function (node in the middle of the penta 0013 % indice i represents the other nodes (the six principal nodes of the penta) 0014 % So that the elementary reduced matrix is Ke_reduced=Kii-Kib*Kbb^-1*Kbi 0015 % See theoryguide for more informations 0016 % 0017 % Usage: 0018 % Ke_reduced=ReduceMatrixStokes(pentaelem,Ke_temp) 0019 % 0020 % See also REDUCEVECTORSTOKES, CREATEKMATRIX 0021 0022 %Create the four matrices 0023 Kii=Ke_temp(1:24,1:24); 0024 Kib=Ke_temp(1:24,25:27); 0025 Kbi=Ke_temp(25:27,1:24); 0026 Kbb=Ke_temp(25:27,25:27); 0027 0028 %Add the components of the matrix for the 6 grids 0029 Ke_reduced=Kii-Kib*Kbb^-1*Kbi;