Circular Ring & Arch Calculator
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Structural Calculator

Circular Ring & Arch Structure Calculator

Real-time bending moment distribution, normal force, hoop stress, and radial deflection for circular rings. Covers diametral point loads, internal pressure, and self-weight load cases.

Parameters
Load Case
Ring Geometry
Mean radius R500 mm
Section width b50 mm
Section height h50 mm
Material & Load
Elastic modulus E200 GPa
Yield stress σ_y250 MPa
Load intensity P / q10.0 kN
M_max [kN·m]
N_max [kN]
Max Stress [MPa]
Max Deflection [mm]
Bending Moment Distribution (full ring)
Normal Force Distribution

Governing Equations

Diametral point loads (angle θ):

$$M(\theta) = \frac{PR}{\pi}\left(1 - \frac{\pi}{2}|\sin\theta|\right), \quad 0 \le \theta \le \pi$$ $$N(\theta) = -\frac{P}{2}\cos\theta - \frac{P}{\pi}|\sin\theta|$$

Internal pressure (uniform radial load q):

$$N = qR \text{ (hoop force)},\quad M = 0,\quad \sigma_\theta = \frac{qR}{t}$$

Combined section stress (rectangular section): $\sigma = \dfrac{N}{A} \pm \dfrac{M \cdot h/2}{I}$

Diametral deflection under point loads:

$$\delta = \frac{PR^3}{EI}\left(\frac{\pi}{4} - \frac{2}{\pi}\right) \times 2$$
CAE Note: Ring theory underpins the analysis of pipe elbows, storage tank rings, and pipeline spans. ASME B31.3 uses the ring flexibility parameter to compute the Stress Intensification Factor (SIF) for curved pipe fittings.