NAFEMS FV12
Modal analysisPASS · 1.44%Free thin square plate with in-plane motion constrained — rigid-body mode filtering and repeated eigenvalues in shell elements.
- Tolerance:
- 5%
Problem statement
- Geometry
- Free thin square plate, modeled with an 8×8 CQUAD4 (shell) mesh.
- Material
- Steel: E = 200 GPa, ν = 0.3, ρ = 8000 kg/m³.
- Boundary conditions
- In-plane motion constrained at all nodes: x-translation, y-translation, and z-rotation fixed; otherwise free (unsupported) plate.
- Measured quantity
- First physical frequencies after the three rigid-body modes, modes 4-9: 1.622, 2.360, 2.922, 4.233, 4.233, 7.416 Hz; mode 10 is a higher-order-estimate (HOE) target of 7.392 Hz, not a closed-form value.
Results comparison
| Reference value | 1.6222.362.9224.2334.2337.416 Hz (моды 4-9) |
| Our result | 1.62432.37062.94374.21424.21427.5231 Hz |
| Deviation | 1.44% |
| Tolerance | 5% |
| Status | PASS · 1.44% |
| Element family | Shell element |
| Mesh details | MITC4-оболочки 16×16, свободная пластина 10×10×0.05 м, in-plane закреплены по постановке, предписанная FV12 сетка 8×8 даёт моды 4-9 = 1.633 / 2.403 / 3.007 / 4.286 / 4.286 / 7.975 Гц (мода 9 на 8×8 отклоняется на 7.5% — чистая дискретизация, сходится) |
Updated: 2026-08-10 · WebCAE solver