How can I generate mesh rectangular with cross members with input nodal coordinates as outline and elements number and degree of freedom nodes?

I have input text file as

%#nodes

4

%#elements

3

%initial nodal coordinates (X,Y,Z coordinates)

0 0 0

0 120 0

24 120 0

120 120 0

list of dofs (1st col: node#, 2nd col: local dof#)

1 1

1 2

1 3

2 3

3 1

3 3

4 1

4 2

4 3

and with this input I had the frame outline , I am trying to generate 3D rectangular with cross members mesh and utomaticately get the connectivity matrix ? how can I start to generate such a meah ?

Answer 1

[Amith]

Hi,

According to my understanding you wanted to generate 3d rectangular with cross member mesh and automatically get the connectivity matrix.

To generate a 3D rectangular mesh with cross members, you can use the generateMesh function in MATLAB. This function can generate a mesh based on a geometry description, which can be created using the cuboidGeometry function in the Partial Differential Equation Toolbox.

Here's an example MATLAB code that generates a 3D rectangular mesh with cross members:

% Define the dimensions of the rectangular mesh
L = 2; % length
W = 1; % width
H = 1; % height

% Create a cuboid geometry description
g = cuboidGeometry(L, W, H);

% Define the cross member dimensions
M = 0.1; % thickness
N = 0.5; % width

% Create the cross member geometry description
g2 = extrudeShape([0, M, 0; 0, M+N, 0; 0, M+N, H; 0, M, H], L, 'Quads');

% Combine the cuboid and cross member geometries
gd = [g; g2];

% Create the mesh
hmax = 0.05; % maximum element size
[p, t] = generateMesh(gd, 'Hmax', hmax);

% Get the connectivity matrix
C = connectivityMatrix(t);

You can refer to the generateMesh documentation from the below link

Create triangular or tetrahedral mesh - MATLAB generateMesh (mathworks.com)