In this lecture, we'll cover the following:

• Comparing results from three models: custom code, OpenSeesPy, and PyNite.
• Assessing agreement in maximum displacement and deflection patterns.
• Evaluating support reactions, particularly discrepancies at slab corners.
• Comparing bending moments, torsional moments, and transverse shear forces.
• Identifying sources of discrepancies due to different finite element implementations.
• Diagnosing issues in the custom model and outlining the need for correction.

In this lecture, we walk through a comparative review of results obtained from three different finite element solutions: our custom implementation, OpenSeesPy, and PyNite. We examine key outputs including maximum displacement, reaction forces, bending and torsional moments, and transverse shear. We observe that the two benchmark models (OpenSeesPy and PyNite) show excellent agreement in both magnitude and qualitative behaviour for most results, with only minor discrepancies - primarily in transverse shear and corner reactions, attributed to differences in element formulations.

We then compare these benchmark results with those from our custom code. While the qualitative patterns (such as displacement shapes and moment distributions) are consistent, indicating that the model is structurally sound, there are notable discrepancies in magnitudes. In particular, the custom model appears too stiff, underpredicting displacements and internal forces. We conclude that the issue is correctable and will be addressed over the next few lectures to bring the results into closer alignment with the benchmark solutions.

Next up

In the next lecture, we will deepen this comparison with a systematic parameter sweep across slab thicknesses, revealing where and why the models diverge.