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MOI_Hemisphere

 

 

This procedure returns mass and moments of inertia of a hemisphere.

 

Inputs

r = radius of sphere [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]

z_bar = distance from centroid to flat surface [m or ft]

 

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

r=0.5 [m]

L=0.4 [m]

rho=990 [kg/m^3]

 

Call moi_hemisphere(r,rho:m, I_x, I_y, I_z, z_bar)

 

{Solution:

I_x=16.81 [kg-m^2]

I_y=16.81 [kg-m^2]

I_z=25.92 [kg-m^2]

z_bar = 0.1875 [m]

m = 259.2 [kg]

}

 

 

Reference:  Gray, G.L, F. Costanzo, R.J. Witt, and M.E. Plesha, Engineering Mechanics: Statics and Dynamics, Third Edition, McGraw Hill, (2023).

 

Moment of Inertia Index