Deep Simply-Supported Beam

NAFEMS Benchmark, Test No. FV5:

$image\fv5.gif$

Summary

Test No. FV5 is a simply-supported beam problem. OptiStruct is used to test the repeated eigenvalues, shear deformation, and rotary inertia. The possibility of missing extensional modes is also investigated.

Benchmark Model

The 2-node beam elements are used to model the simply-supported beam which consists of 5 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. The material properties for the beam are: $image\evp.gif$ .

Modal Analysis Results

The frequency of each targeted mode is normalized with the closed form solution.

f* = closed form solution

Modes 1 & 2 Flexural		Mode 3 Torsional		Mode 4 Extensional
f* CBEAM	42.649 Hz 1.0124	f* CBEAM	77.542 Hz 0.9157	F* CBEAM	125.00 Hz 1.0000

Modes 5 & 6 Flexural		Mode 7 Torsional		Modes 8 & 9 Flexural
f* CBEAM	148.31 Hz 1.0409	f* CBEAM	233.10 Hz 0.8840	f* CBEAM	284.55 Hz 1.0725

Reference

NAFEMS Ltd, The Standard NAFEMS BENCHMARKS TNSB Rev. 3, NAFEMS Ltd, Scottish Enterprise Technology Park, Whitworth Building, East Kilbride, Glasgow, United Kingdom, 1990.

Return to Altair HyperWorks Index