FEATool Multiphysics  v1.16.4 Finite Element Analysis Toolbox
gridmerge.m File Reference

Description

GRIDMERGE Merge two grids.

[ GRID ] = GRIDMERGE( GRID1, IND1, GRID2, IND2, I_DELETE, I_CHECK ) Merges the matching boundaries edges and faces specified by boundary numbers IND1 in GRID1 and IND2 in GRID2. The algorithm tries to match up the boundary with the fewest boundary edges/faces and nodes to the closest corresponding ones on GRID2. The optional argument I_DELETE selects which grid to delete duplicate nodes from (I_DELETE is 2 per default). I_CHECK toggles error checking on/off.

Can optionally be called as GRIDMERGE( GRID1, GRID2 ) where IND1 and IND2 are determined by any shared boundary numbers (also in this case boundaries and subdomains are not renumbered).

Examples
  1) Create a 2D rivet by joining a rectangle and half circle.

grid1 = rectgrid( 4, 10, [0.3 0.7;0 1] );
grid2 = circgrid( 4, 3, 0.5, [0.5;1] );
grid2 = delcells( grid2, 'y<=1' );
grid  = gridmerge( grid1, 3, grid2, 4 );

2) Create a flow over cylinder benchmark grid by merging three grids.

grid1 = ringgrid( [0.05 0.06 0.08 0.11 0.15], 32, [], [], [0.2;0.2] );
grid2 = holegrid( 8, 1, [0 0.41;0 0.41], 0.15, [0.2;0.2] );
grid2 = gridmerge( grid1, 5:8, grid2, 1:4 );
grid3 = rectgrid( [0.41 0.5 0.7 1 1.4 1.8 2.2], 8, [0.41 2.2;0 0.41] );
grid  = gridmerge( grid3, 4, grid2, 6 );

3) Create a 3D grid with two brackets attached to an I-beam section.

grid01 = ringgrid( 1, 20, 0.03, 0.06, [0;0] );
indc01 = selcells( grid01, 'y<=sqrt(eps)' );
grid01 = delcells( grid01, indc01 );

grid02 = holegrid( 5, 1, .06*[-1 1;-1 1], .03, [0;0] );
indc02 = selcells( grid02, 'y>=-sqrt(eps)' );
grid02 = delcells( grid02, indc02 );
grid2d = gridmerge( grid01, [5 6], grid02, [7 8] );

grid1 = gridextrude( grid2d, 1, 0.02 );
grid1 = gridrotate( grid1, pi/2, 1 );
grid2 = grid1;
grid1.p(2,:) = grid1.p(2,:) + 0.03;
grid2.p(2,:) = grid2.p(2,:) - 0.01;

x_coord = [ -0.08 linspace(-0.06,0.06,6) 0.08 ];
y_coord = [ -0.2 -0.15 -0.1 -0.05 -0.03 -0.01 ...
0.01  0.03  0.05  0.1  0.15  0.2 ];
grid3 = blockgrid( x_coord, y_coord, 1, ...
[-0.08 0.08;-0.2 0.2;-0.08 -0.06] );
grid4 = blockgrid( 1, y_coord, 5, ...
[-0.01 0.01;-0.2 0.2;-0.18 -0.08] );
grid5 = grid3;
grid5.p(3,:) = grid5.p(3,:) - 0.12;

grid = gridmerge( grid1, 8, grid3, 6 );
grid = gridmerge( grid2, 8, grid, 19 );
grid = gridmerge( grid4, 6, grid, 24, 1 );
grid = gridmerge( grid5, 6, grid, 33, 2 );