Relationship between mass moment of inertia and second moment of area?

Fat Ryan

I am trying to create a model in SimMechanics of a simple damped frame. I am very new to this software and structural dynamics as well. I have a copy of "Dynamics of Structures" 3ed by Chopra. In the textbook, the author uses the standard geometric and material properties that I am familiar with to obtain stiffnesses (modulus of elasticity, E & second moment of area, I). Simscape, however, asks for mass and inertia tensor. The latter of which has units of mass*length^2. Is there some sort of relationship between the area moment of inertia and mass moment of inertia? The reason it of importance is because I need to create this model and verify it somehow. If I replicate an example in the textbook, then obviously I'll know if I'm doing things correctly. Unfortunately, the textbook only provides area moment of inertia in it's examples.

viscousflow

Sorry, the two are totally independent of each other.

Fat Ryan

hmm, does anyone know why there's a difference between the book and simscape then?

leosc

This isn't really true...

They are different, but still dependent/related to each other...
I've never found this in a book,
but one can show the relation between them by using balance of linear momentum...

The relation is the following:

I_mass = [tex]\rho[/tex]_area * I_area

where

I_mass : Mass Moment of Inertia
I_area : Area Moment of Inertia
[tex]\rho[/tex]_area : area density (kg/m²)

enigma

Assuming constant density...

leosc

Yes, I forgot to mention that. Thanks!