Contents - Index


Prism

 

 

This procedure returns mass and moments of inertia of a rectangular prism'

 

Inputs

a =width [m, ft]

b=height [m, ft]

c= length [m, ft]

rho = material density [kg/m^3, lbm/ft^3]

 

Outputs

m=mass [kg, lb_m]

I_x = moment of inertia about the x-axis [kg-m^2 or lbm-ft^2]

I_y= moment of inertia about the y-axis [kg-m^2 or lbm-ft^2]

I_z = moment of inertia about the z-axis [kg-m^2 or lbm-ft^2]

 

Example:   

$Load Mechanical Design

$UnitSystem SI K Pa 

$VarInfo I_x units=kg-m^2

$VarInfo I_y units=kg-m^2

$VarInfo I_z units=kg-m^2

a=0.25 [m] 

b=0.35 [m]

c=0.4 [m]

rho=990 [kg/m^3]

Call  moi_prism(a, b, c, rho:m, I_x, I_y, I_z)

 

{Solution:

I_x=0.5342 [kg-m^2]

I_y=0.6425 [kg-m^2]

I_z=0.8157 [kg-m^2]

m = 34.65 [kg]

}

 

Reference:  Juvinall and Marshek, 5th edition, Fundamentals of Machine Component Design, Appendix B-2

 

Moment of Inertia Index