Moment of Inertia Formula:
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The moment of inertia (I) for a rectangle is a measure of its resistance to bending about a particular axis. For a rectangle about its centroidal axis, it's calculated using the base (b) and height (h) dimensions.
The calculator uses the moment of inertia formula:
Where:
Explanation: The formula shows that the moment of inertia increases with the cube of the height, making height dimension more significant than base in determining bending resistance.
Details: Moment of inertia is crucial in structural engineering for calculating beam deflection, stress analysis, and designing structural elements to withstand bending loads.
Tips: Enter base and height in meters. Both values must be positive numbers. The result will be in kg·m² units.
Q1: What axis does this formula apply to?
A: This formula calculates moment of inertia about the centroidal axis parallel to the base.
Q2: How does orientation affect the calculation?
A: The base and height are relative to the axis being considered. Swap values if calculating about the other centroidal axis.
Q3: What are typical values for structural beams?
A: For steel I-beams, moments of inertia typically range from 10⁻⁶ to 10⁻³ m⁴ depending on size.
Q4: Can this be used for composite shapes?
A: For composite shapes, use the parallel axis theorem to combine moments of inertia of individual rectangles.
Q5: How does material affect moment of inertia?
A: Material properties don't appear in this geometric calculation. Material strength affects stress, not the moment of inertia itself.