This brief article explains the difference between linear and non-linear analyses applied on a structure.
The difference depends on several parameters, such as:
- mechanical behaviour of the structure (it depends on the construction material);
- displacements of the structure;
- boundary conditions.
A linear analysis mainly requires linear elastic material and small displacements (infinitesimal strain theory), while a non-linear analysis considers large displacements and elastoplastic materials, therefore the superposition effect cannot be applied.
Another important difference is the stiffness matrix. In fact, the stiffness matrix remains constant during a linear analysis, but this phenomenon does not apply to a non-linear analysis.
The role played by these parameters and a logical approach are important to understand theory behind these analyses. Modern software studies the structure with both methods, but the engineer must choose which method use.
I hope you found this article informative and useful. If you have any questions, please do not hesitate to contact me.
