2D LINEAR TRUSS FINITE ELEMENT

This program computes the displacements, support reactions, and stresses for a 2D truss system.

The formulation is for 2-noded elements with first order linear shape functions. Each global node has 2 degrees-of-freedom - one in the x-direction and one in the y-direction. The system of linear equations (SLE) is solved for by eliminating the i-th rows and i-th columns for which u(i)=0 (boundary conditions).

The "preprocessor" section is based on an example 2-element truss system (please see image). A user is required to input the following truss information: node ID, degree-of-freedom (dof) indices, nodal coordinates, element ID, element end-node IDs, element cross-section, element Young's modulus, boundary conditions (i.e., support conditions), and applied forces.

A user must follow the general input format I used here. All inputs are defined in the "preprocessor" section and there should be no need to modify anything under the "generic algorithm" section (unless you want to). The algorithm should generally work for any simple 2D truss configuration.