MATLAB Code for Solving two-dimensional truss

Solving the truss using the stiffness method.

The steps of solving the truss by the stiffness method:

1. Numbering of nodes and elements
2. Specifying the length of each element
3. Obtaining sin and cosz
4. Forming the stiffness matrix of each member
5. Forming the total stiffness matrix
6. Writing the relationship F = K U in matrix form
7. Removing rows and columns that can be removed from the above matrix
8. Solve the above matrix and get U or displacements
9. Obtaining the stress in each member
10. Obtaining support reactions

To use this code, just add the specifications of the truss you want to the Excel file and run the Truss2DD.m file.

Program outputs include:

1. Stiffness matrix
2. load vector
3. Displacement
4. Stress
5. Reaction
6. Truss Shape(black)
7. ِDeformed Shape(red)

Outputs for 4Bar-Truss:

load =

0

0

2000

0

0

-25000

0

0

JointDisp =

0

0

0.0027

0

0.0056

-0.0222

0

0

Stress =

1.0e+04 *

0.2000

-2.1875

-0.5208

0.4167

Reaction =

1.0e+04 *

0.2167

0.3125

0.2000

2.1875

0.0000

-2.5000

-0.4167

0