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Hello,
Can modalDamping command be used to specify different damping ratios for different modes. If so what is the signature (format) of the command call for assigning different damping ratios to different modes??

Regards

tguha

Hello, Can someone suggest a way to release bending moment at the end nodes (I and J node) of a beamColumn element that is not co-aligned to any of the principal axes (Global X, Y and Z axes). I understand one way to accomplish this, if the beamColumn element is aligned to the Global X,Y,Z axes (tha...

Hello, Does a fiber section only handle the axial force-bending moment interaction under biaxial bending and not axial torsion for beamColumnElement used as a beam in 3D problem. How can I record the torsional force-deformation in a beamcolumn section for a beam subjected to torsion?? Regards Tushar

Hello, Can someone kindly explain the output of an element recorder when recording the force, deformation and stressStrain (fiber) of a non-linear beam column element (forceBeamColumn) used as a beam in a 3D problem subjected to both flexure (along local y and z direction) and torsion (along local x...

Hello, I want to use a forceBeamColumn element as a beam through the use of an aggregator section for non-linear (dynamic) time history analysis of a structure. The aggregator section I use in the forceBeamColumn command in turn has six non-linear stress strain material models (Steel02) parametrical...

Hello, Viscous(oil) dampers are typically provided with a release value to bypass the oil during high force on the dampers. The force-velocity relation for such dampers is typically bi-linear i.e. high damping coefficient up to a certain threshold restoring force (linearly proportional to velocity),...

Hello, I wanted to know the difference between the way to use Rayleigh damping in a structural analysis vs the way to use viscous damper elements. More specifically, if I know the viscous properties (storage stiffness, damping coefficient and alpha) of the visco-elastic damper installed in the struc...

Thank you for the response. So for shell elements in the model (that I am using to model a thin plate structure), I can assign the density of the plate fiber section without having to assign nodal masses of the four corner nodes making up the shell element. And for elastic beam-column sections, I ne...

Hello, Do I need to explicitly assign nodal masses for eigen value analysis in Opensees?? Or whether if I assign densities to the element types in the model along with the lumped mass option, then nodal masses (for dead load along the vertical axis) are automatically calculated based on statically e...

Hello, I am trying to carry out a transient analysis under wind loading on a solar racking system in which the solar modules are inclined at 30 degree to the horizontal plane (ground), the x-z plane. The problem is 3 dimensional with 6 degrees of freedom. The y-axis is vertical to the ground (direct...