1. Model: Large Deformation Beam

2. Introduction
This example shows the deflection of a cantilever beam undergoing very large deflections.
The model is called “Straight cantilever GNL Benchmark” and is described in detail in the NAFEMS report “Background to Finite Element Analysis of Geometric Non-linearity Benchmarks”.

3. Problem definition Fy Fx
The beam is linear elastic, with E = and n=0.
The left end is fixed.
The right end is subjected to distributed loads. Fx = and Fy=

4. Results
The final state (using 1:1 displacement scaling) is shown in the figure.
Due to the large compressive axial load, this is a buckling problem. It is necessary to perturb the symmetry somewhat. The small transversal load (Fy) serves this cause.

5. Results
The vertical (solid line) and horizontal (dashed line) displacements for varying load (Fx).
The results are in excellent agreement with the NAFEMS report.