Matlab平面网格划分

% To Mesh a Circular Plate with 4 and 3 noded Elements %-------------------------------------------------------------------------- % Code written by : Siva Srinivas Kolukula | % Senior Research Fellow | % Structural Mechanics Laboratory | % Indira Gandhi Center for Atomic Research | % India | % E-mail : allwayzitzme@gmail.com | % http://sites.google.com/site/kolukulasivasrinivas/ | %-------------------------------------------------------------------------- %-------------------------------------------------------------------------- % Purpose: % To Mesh a circular plate to use in FEM Analysis % Variable Description: % Radius - Radius of the Plate % theta - Angle of the sector to which Plate needed % NR - Number of Elements along Radius (Number of Rings) % NT - Number of Angular sectors % coordinates - The nodal coordinates of the mesh % -----> coordinates = [node X Y] % nodes - The nodal connectivity of the elements % -----> nodes = [element node1 node2......] % NOTE : If the node number repeats take it as Triangular Element %-------------------------------------------------------------------------- Radius = 1. ; % Radius of the plate theta = 90. ; % Angle of the plate % NR = 7 ; NT = 10 ; %-------------------------------------------------------------------------- % From here dont change nel = NR*(NT-1) ; % Total Number of Elements in the Mesh nnel = 4 ; % Number of nodes per Element % Number of points on the Radius and Angluar discretization npR = NR+1 ; npT = NT ; % Discretizing the Length and Breadth of the plate nR = linspace(0,Radius,npR) ; nT = linspace(0,theta,npT)*pi/180 ; %nT = pi/180*(0:NT:theta) ; [R T] = meshgrid(nR,nT) ; % Convert grid to cartesian coordintes XX = R.*cos(T); YY = R.*sin(T); % ZZ = zeros(size(XX)) ; % mesh(XX,YY,ZZ) ; % To get the Nodal Connectivity Matrix coordinates = [XX(:) YY(:)] ; if nR(1)==0 nnode = npR*npT-(NT-1) ; % Total Number of Nodes in the Mesh NodeNo = [ones(1,NT-1),1:nnode] ; coordinates = coordinates(NT:end,:) ; else nnode = npR*npT ; % Total Number of Nodes in the Mesh NodeNo = 1:nnode ; end nodes = zeros(nel,nnel) ; % If elements along the X-axes and Y-axes are equal if npR==npT NodeNo = reshape(NodeNo,npT,npR); nodes(:,1) = reshape(NodeNo(1:npR-1,1:npT-1),nel,1); nodes(:,2) = reshape(NodeNo(2:npR,1:npT-1),nel,1); nodes(:,3) = reshape(NodeNo(2:npR,2:npT),nel,1); nodes(:,4) = reshape(NodeNo(1:npR-1,2:npT),nel,1); % If the elements along the axes are different else%if npR>npT NodeNo = reshape(NodeNo,npT,npR); nodes(:,1) = reshape(NodeNo(1:npT-1,1:npR-1),nel,1); nodes(:,2) = reshape(NodeNo(2:npT,1:npR-1),nel,1); nodes(:,3) = reshape(NodeNo(2:npT,2:npR),nel,1); nodes(:,4) = reshape(NodeNo(1:npT-1,2:npR),nel,1); end % % Plotting the Finite Element Mesh % Initialization of the required matrices X = zeros(nnel,nel) ; Y = zeros(nnel,nel) ; % Extract X,Y coordinates for the (iel)-th element for iel = 1:nel X(:,iel) = coordinates(nodes(iel,:),1) ; Y(:,iel) = coordinates(nodes(iel,:),2) ; end % Figure fh = figure ; set(fh,'name','Preprocessing for FEA','numbertitle','off','color','w') ; patch(X,Y,'w') title('Finite Element Mesh of Circular Plate') ; %axis([0. L*1.01 0. B*1.01]) axis off ; axis equal ; % To display Node Numbers % Element Numbers pos = [70 20 60 20] ; ShowNodes = uicontrol('style','toggle','string','nodes','value',0,.... 'position',[pos(1) pos(2) pos(3) pos(4)],'background','white','callback',... 'SHOWNODES(ShowNodes,ShowElements,coordinates,X,Y,nnode,nel,nodes)'); pos = get(ShowNodes,'position') ; pos = [2*pos(1) pos(2) pos(3) pos(4)] ; ShowElements = uicontrol('style','toggle','string','Elements','value',0,.... 'position',[pos(1) pos(2) pos(3) pos(4)],'background','white','callback',.... 'SHOWELEMENTS(ShowElements,ShowNodes,coordinates,X,Y,nel,nodes,nnode)');