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: Quadrangle
- Plate Corner 1 Coordinates: 0, 0, 0 m
- Plate Corner 2 Coordinates: 1, 1, 0 m
- Plate Corner 3 Coordinates: 1, 1.5, 0 m
- Plate Corner 4 Coordinates: 0, 1, 0 m
- Plate Thickness: 5 mm
- Left-Edge Supports: FFFFFF (Fixed)
- Point Load: 1 kN +Y vertical at Plate Corner 2
Results – 5×5 Structured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Min Displacement X (mm) | Node 3 | -0.01557 | -0.01389 | 12.10% | -0.01557 | 0.00% |
| Max Displacement Y (mm) | Node 3 | 0.01844 | 0.01541 | 19.66% | 0.01844 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 5 Top | 1.68643 | 1.91644 | -12.00% | 1.67746 | 0.53% |
| Max Membrane Force XY – Element (kN/m) | Element 21 | 3.01272 | 2.70639 | 11.32% | 2.91848 | 3.23% |
| Reaction Y | Node 15 | -0.33642 | -0.29053 | 15.80% | -0.33642 | 0.00% |
| Reaction X | Node 15 | -0.63959 | -0.61917 | 3.30% | -0.63959 | 0.00% |
Results – 20×20 Structured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Min Displacement X (mm) | Node 3 | -0.01564 | -0.01551 | 0.84% | -0.01564 | 0.00% |
| Max Displacement Y (mm) | Node 2 | 0.02020 | 0.02010 | 0.50% | 0.02020 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 20 Top | 5.52230 | 6.42078 | -13.99% | 5.49870 | 0.43% |
| Max Membrane Force XY – Element (kN/m) | Element 381 | 5.84653 | 5.65927 | 3.31% | 5.79700 | 0.85% |
Results – Unstructured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Min Displacement X (mm) | Node 3 | -0.01556 | ERR | – | -0.01556 | 0.00% |
| Max Displacement Y (mm) | Node 3 | 0.01982 | ERR | – | 0.01982 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 82 Top | 3.68514 | ERR | – | 3.69233 | -0.19% |
| Max Membrane Force XY – Element (kN/m) | Element 112 | 5.01036 | ERR | – | 4.59800 | 8.97% |
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
