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

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.

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 Sorry, the two are totally independent of each other.

 Quote by viscousflow Sorry, the two are totally independent of each other.
hmm, does anyone know why there's a difference between the book and simscape then?

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

 Quote by viscousflow Sorry, the two are totally independent of each other.
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:

Imass = $$\rho$$area * Iarea

where

Imass : Mass Moment of Inertia
Iarea : Area Moment of Inertia
$$\rho$$area : area density (kg/m²)

 Recognitions: Gold Member Science Advisor Staff Emeritus Assuming constant density...

 Quote by enigma Assuming constant density...
Yes, I forgot to mention that. Thanks!