Eigenvalue analysis is often a necessary step before starting a dynamic response history analysis in OpenSees. You may want natural frequencies in order to compute Rayleigh damping coefficients, to apply modal damping, to compute modal properties, or to perform a response spectrum or modal superposition analysis. However, eigenvalue analysis can fail, indicating a problem with … Continue reading Why Your Eigenvalue Analysis Failed
Tag: Vibration
Distributed Mass Beam Vibration
Most beam-column elements in OpenSees take mass density, $latex \rho$ (mass per unit length), as an input. The elements then return lumped mass $latex \rho L/2$ for the translational DOFs at the element ends. The elasticBeamColumn element can also return a consistent mass matrix with the -cMass input option. ops.element('elasticBeamColumn',tag,...,'-mass',rho,'-cMass') The dispBeamColumn and forceBeamColumn elements … Continue reading Distributed Mass Beam Vibration
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