Centroid
Definition
The geometric center of a cross-section, where the first moment of area equals zero. For symmetric shapes, the centroid lies on the axis of symmetry. Moments of inertia are typically calculated about axes through the centroid.
Practical Note
Finding the centroid is the first step in section property calculations. For composite sections, use weighted average: ȳ = Σ(Aᵢyᵢ)/ΣAᵢ. The neutral axis passes through the centroid in pure bending.
Related Calculators
📐Moment of Inertia Calculator
Calculate moment of inertia (second moment of area), section modulus, and radius of gyration for common cross-sectional shapes including rectangles, circles, I-beams, and channels.
📐Beam Deflection Calculator
Calculate maximum deflection, bending moment, and stress for simply supported and cantilever beams. Includes 3D visualization.