Model Details and Parameters
The purpose of this test case is to validate the plate/shell element solver in SkyCiv Structural 3D (S3D). The results were compared against a third-party analysis software. In this test case the following model parameters were used:
- Analysis Type: Linear Static
- Material: Structural Steel
- Young’s Modulus: 200,000 MPa
- Poisson’s Ratio: 0.27
- Plate Type: Mindlin Plane Stress
- Plate Size: 2m x 1m
- Plate Thickness: 10 mm
- Corner Supports: FFFFFF (Fixed)
- Pressure Load: 1 kPa normal to plate

Results – 8×4 Structured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Max Displacement Z (mm) | Node 8 (center of longer edge) | -5.69238 | -4.37686 | 30.06% | -5.69238 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 1 Top | 15.73128 | 17.09678 | -7.99% | 15.73128 | 0.00% |
| Reaction Z (kN) | Node 1 | 0.50000 | 0.50000 | 0.00% | 0.50000 | 0.00% |
| Reaction Moment Y (kN-m) | Node 1 | -0.10862 | -0.12947 | -16.10% | -0.10862 | 0.00% |
| Min Moment XY – Element (kN-m/m) | Element 2 | -0.06800 | -0.08874 | -23.37% | -0.06800 | 0.00% |
Results – 16×8 Structured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Max Displacement Z (mm) | Node 12 (center of longer edge) | -6.46124 | -5.41539 | 19.31% | -6.46124 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 1 Top | 37.97616 | 39.13067 | -2.95% | 37.97616 | 0.00% |
| Reaction Z (kN) | Node 1 | 0.50000 | 0.50000 | 0.00% | 0.50000 | 0.00% |
| Reaction Moment Y (kN-m) | Node 1 | -0.09903 | -0.11470 | -13.66% | -0.09903 | 0.00% |
| Min Moment XY – Element (kN-m/m) | Element 1 | -0.21176 | -0.23954 | -11.60% | -0.21176 | 0.00% |
Results – Unstructured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Max Displacement Z (mm) | Node 12 (center of longer edge) | -6.89866 | -5.69793 | 21.07% | -6.89991 | -0.02% |
| Max Von Mises Stress – Element (MPa) | Element 204 Top | 53.44921 | 54.29362 | -1.56% | 52.96061 | 0.92% |
| Reaction Z (kN) | Node 1 | 0.49931 | 0.50013 | -0.16% | 0.49938 | -0.01% |
| Reaction Moment Y (kN-m) | Node 1 | -0.09257 | -0.10936 | -15.35% | -0.09259 | -0.02% |
| Min Moment XY – Element (kN-m/m) | Element 1 | -0.31325 | -0.35302 | -11.27% | -0.31326 | 0.00% |

Extra Considerations
- This verification model was created and checked on 28 February 2020. Since this date, the plate solver and S3D software may have been further improved to achieved greater accuracy.
- Plates are not exact elements like beam and frame elements and therefore the mesh plays a huge role in the results. Always try to use a structured mesh when it is possible to do so.
- Results between software will never be exactly the same since different elements are used and the nature of plates are approximate

