Maximum deflection for simply supported circular plate?

δ_max = (3q a⁴ (5+ν)(1-ν))/(16 E t³ (1+ν)) at centre

When to use thin vs thick plate theory?

Thin: t < 1/10 span. Thick: include shear deformation.

AutoEngCalc - Engineering Calculators

Plate Stress Calculator

Calculate maximum bending stress, deflection and moments in rectangular and circular plates under uniform or point loading. Simply supported or clamped edges.

Max Deflection

2.8 mm

Circular plate, q=10 kPa, a=0.5m

Plate Bending Analysis

Featured: Max Stress • Deflection • Moments • Rectangular/Circular

Plate Shape

Edge Support

Radius a or Length a (m)

Width b (m) - Rectangular

Thickness t (mm)

Young's Modulus E (GPa)

Poisson's Ratio ν

Load Type

Load q (kPa) or P (kN)

Deflection Profile

Cross-section view

Kirchhoff Thin Plate Theory

D = E t³ / (12 (1-ν²))
∇⁴w = q / D

Enter plate parameters to see results

Plate Analysis Guidelines

Circular Plate (Clamped)

Uniform: δ_max = q a⁴ / (64 D)

Point: δ_max = P a² / (16 π D)

σ_max: at edge

Rectangular Plate

Simply supported: δ_max ≈ 0.00416 q a⁴ / D (square)

Clamped: lower deflection

Aspect ratio: affects coefficients

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