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
- Edge Boundary Supports: FFFRRR (3D Pin)
- 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 25 (center of plate) | -0.54879 | -0.56405 | -2.71% | -0.54879 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 20 Top | 4.63425 | 4.82904 | -4.03% | 4.63432 | 0.00% |
| Reaction Z (kN) | Node 21 | 0.12649 | 0.12961 | -2.41% | 0.12649 | 0.00% |
| Max Shear Force XZ – Element (kN/m) | Element 28 | 0.29475 | 0.33767 | -12.71% | 0.29475 | 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 120 (center of plate) | -0.55999 | -0.56542 | -0.96% | -0.55999 | 0.00% |
| Max Von Mises Stress – Element (MPa) | Element 72 Top | 5.11488 | 5.17574 | -1.18% | 5.11487 | 0.00% |
| Reaction Z (kN) | Node 71 | 0.06218 | 0.06307 | -1.41% | 0.06218 | 0.00% |
| Max Shear Force XZ – Element (kN/m) | Element 120 | 0.35126 | 0.40086 | -12.37% | 0.35125 | 0.00% |
Results – Unstructured Mesh
| Result | Location | SkyCiv | Third-Party 1 | Difference 1 | Third-Party 2 | Difference 2 |
| Max Displacement Z (mm) | Node 182 (center of plate) | -0.55988 | -0.56293 | -0.54% | -0.55932 | 0.10% |
| Max Von Mises Stress – Element (MPa) | Element 170 Top | 5.22850 | 5.25876 | -0.58% | 5.22487 | 0.07% |
| Reaction Z (kN) | Node 59 | 0.04218 | 0.04217 | 0.02% | 0.04214 | 0.09% |
| Max Shear Force XZ – Element (kN/m) | Element 62 | 0.44973 | 0.49276 | -8.73% | 0.45013 | -0.09% |
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