OS-V: 0415 Deep Simply-Supported Beam
Test No. FV5 OptiStruct tests the repeated eigenvalues, shear deformation, and rotary inertia. The possibility of missing extensional modes is also investigated.

Figure 1. FE Model with Boundary Conditions and Loadcases
Benchmark Model
The 2-node beam elements are used to model the simply-supported beam which consists of five elements. The displacements in x, y, and z direction, as well as the rotation in x direction are fixed at the end A. In addition, the displacements in y and z direction are constrained at end B.
- Property
- Value
- E
- 200 x 109 N/m2
- 0.3
- 8000 kg/m3
Modal Analysis Results
f*
- Closed form solution.
Modes 1 and 2 Flexural | Mode 3 Torsional | Mode 4 Extensional | |||
---|---|---|---|---|---|
f* CBEAM 42.649 Hz |
42.649 Hz 1.0124 |
f* CBEAM 77.542 Hz |
77.542 Hz 0.9157 |
f* CBEAM |
125.00 Hz 1.0000 |
Modes 5 and 6 Flexural | Mode 7 Torsional | Modes 8 and 9 Flexural | |||
---|---|---|---|---|---|
f* CBEAM 42.649 Hz |
148.31 Hz 1.0409 |
f* CBEAM |
233.10 Hz 0.8840 |
f* CBEAM |
284.55 Hz 1.0725 |
Model Files
The model file used in this problem includes:
<install_directory>/hwsolvers/demos/optistruct/verification/fv5.fem
Reference
NAFEMS Ltd, The Standard NAFEMS BENCHMARKS TNSB Rev. 3, NAFEMS Ltd, Scottish Enterprise Technology Park, Whitworth Building, East Kilbride, Glasgow, United Kingdom, 1990.