The Parallel Axis Theorem

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The Parallel Axis Theorem

• The parallel axis theorem is used with the method
  of composite parts.

If Ix is known for centroidal axis how to get it
for any other parallel axis?
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Theorem

• Proof
• I WRT lower axis
• WRT centroidal axis

y yd
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more

• I

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Other Parallel Axis Theorems

• Radius of gyration
• Polar moment of inertia

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The Rectangle

• Given Ix, Iy . Compute Recall
• Ix bh3/3
• Iy b3h/3

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Composite Parts

• Area composed of simple shapes.

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