A simply supported beam is analyzed to determine the fundamental frequency. Determine the fundamental frequency.
Analysis Type
2-D eigenvalue analysis (X-Z plan)
Unit System
in, lbf
Dimension
Length 80in
Element
Beam element
Material
Modulus of elasticity E = 30.0×10^6psi
Weight density γ = 0.281 lbf/in^3
Sectional Property
Rectangular cross-section: b = 2 in, h = 2 in
Boundary Condition
Node 1, 5: Constrain DX and DZ
Analysis Case
Eigenvalue analysis
App
Object Link : https://openbrim.org/objidymyvks7hfy993hllthc.project
Library
Object Link : https://openbrim.org/objid4rrxuzza7lcslvnwzvsqo.libobj
References
Thomson, W. T., (1965). “Vibration Theory and Application”, Prentice Hall, Englewood Cliffs, N. J.




TheoreticalMIDASOpenBrim

Percent Difference

(MIDAS vs Theoretical)

Percent Difference

(OpenBrim vs Theoretical)

Mode 1 

Frequency (Hz)28.76628.75928.74510.02%0.07%
Period (sec)0.03480.0350.03480.6%0%