Modal mass and a cantilever column 1

[RK Sriwastav]

I have been checking the effect on model mass by modelling a simple cantilever column fixed at the base. I have given the self weight of the column as zero.
The lumped mass are applied in the free end in x,y and z directions. No additional loading is applied. Mass source is fixed as the element masses and additional mass.

While analyzing this model, I am not getting any vertical displacement or axial force in the column. What could be the Problem ?



Ravi K

 

[JoshPlumSE]

What load are you applying? A time history load, response spectra load, or what? Does that load have any component in the vertical direction?

 

[RK Sriwastav]

I am not applying any load. I am carrying out only static gravity analysis. My understanding is because of application of lumped mass at the free end there should be deflection and axial load generated in the column.

Ravi K

 

[JoshPlumSE]

I believe the mass matrix and the load matrix are defined separately. Where Mass is only used for the dynamic analysis. For static analysis you have to define the load yourself. There MIGHT be a way to automatically convert applied load into joint masses. But, I'm pretty sure there isn't a way to do it the other way around.

 

[RK Sriwastav]

Thank you @JoshPlum. The reason that i am not getting the response is "no application of load in gravity load analysis" as you have suggested.

Ravi K