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 →