Equation is given for the maximum stress and deflection for circular flat plates subject to concentrated or distributed loads (pressure) with the edge either clamped or supported. In practice, the edge conditions are usually uncertain and some compromise must be made. The equations are only valid if the deflection is small compared to the plate thickness.

Symbols used:
r = radius of circular plate, (m, in)
p = uniform loading, (N/m², lbs/in²)
v = Poisson’s ratio (assumed to be 0.3)
E = Young’s modulus, (N/m², lbs/in²)
t = plate thickness, (m, in)
σ _m = maximum stress, (N/m², lbs/in²)
y_m = maximum deflection, (m, in)

Circular plate, uniform load, edges simply supported equation and calculator.

Stress At Center

Deflection at center, v = 0.3

D = flexural rigidity= Et³/(12 * ( 1 -v²)