Supplementary Material, Appendix G – G.3

APPENDIX G – Pumps and Turbines

MainPreviousNext

Surge Analysis and the Wave Plan Method

Supplementary Material: Example Problems and Solutions

Appendix G – Problem 3

G.3 Compute the area moment of inertia (I) of a thin circular steel plate of 300 mm diameter with respect to its principal x-axis as well as the centerline z-axis perpendicular to its surface. Compute the radius of gyration of this plate with respect to both x and z axes. 

Solution:

Area moment of inertia through principal x-axis = Ix

Ix = (π/4) r4 = 0.25 * π * 0.154 = 0.000398 m4

Radius of gyration Rx = (Ix/Area)0.5

Area = πr2 = 0.0707 m2, Rx = 0.075 m (or r/2)

Area moment of inertia through the centerline axis perpendicular to the surface, also referred to as polar moment of inertia = Iz

Iz =  2 Ix  = (1/2) πr4 = 0.5 * π * 0.154 = 0.000795 m2

Radius of gyration Rz = (Iz/Area)0.5 = 0.1061m (or r/√2)


Summary of revisions to this page:

Date/Revision