PASS/NOZZLE-FEM 3.5. Program Manual

4.2. Stress analysis by FEM

Allowable stresses in accordance with GOST 34233.1-2007

Mesh level = 1

Safety factor allowed for mesh level: K_m = 1.05

Shell material properties

Nominal allowable stresses for material St3 at the temperature 100^°C:

[σ] = = 1 / 1.05 * min{201 / 1.5; 360 / 2.4} = 127.6 MPa

Elasticity modulus at the temperature 100^°C:

E = 1.91·10⁵ MPa

Nozzle material properties

Nominal allowable stresses for material St3 at the temperature 100^°C:

[σ]₁ = = 1 / 1.05 * min{201 / 1.5; 360 / 2.4} = 127.6 MPa

Elasticity modulus at the temperature 100^°C:

E₁ = 1.91·10⁵ MPa

Reinforcement area material properties

Nominal allowable stresses for material St3 at the temperature 100^°C:

[σ]₂ = = 1 / 1.05 * min{201 / 1.5; 360 / 2.4} = 127.6 MPa

Elasticity modulus at the temperature 100^°C:

E₂ = 1.91·10⁵ MPa

Fig. 4.1. Finite-element model of branch connection

Fig. 4.2. Equivalent membrane stresses from combined action of forces and pressure, MPa

Conclusion:

For shell For shell σ_ml max = 168.05  ≤ 1.5[σ] = 191.43 MPa.

Strength condition is SATISFIED.

For nozzle σ_1ml max = 168.05  ≤ 1.5[σ]₁ = 191.43 MPa.

Strength condition is SATISFIED.

For reinforcement area For reinforcement area σ_2ml max = 102.61  ≤ 1.5[σ]₁ = 191.43 MPa.

Strength condition is SATISFIED.

Fig. 4.3. Total (membrane and bending) stresses on the outside surface, MPa

Conclusion:

For shell σ_mb max = 237.03  ≤ 3[σ] = 382.86 MPa.

Strength condition is SATISFIED.

For nozzle σ_1mb max = 237.03  ≤ 3[σ]₁ = 382.86 MPa.

Strength condition is SATISFIED.

For reinforcement area σ_2mb max = 147.53  ≤ 3[σ]₂ = 382.86 MPa.

Strength condition is SATISFIED.

Fig. 4.4. Total (membrane and bending) stresses on the inside surface, MPa

Conclusion:

For shell σ_mb max = 283.93  ≤ 3[σ] = 382.86 MPa.

Strength condition is SATISFIED.

For nozzle σ_1mb max = 283.93  ≤ 3[σ]₁ = 382.86 MPa.

Strength condition is SATISFIED.

For reinforcement area σ_2mb max = 75.61  ≤ 3[σ]₂ = 382.86 MPa.

Strength condition is SATISFIED.

General conclusion: Strength conditions are satisfied.