Dear Ruijie Wang,

Hello, and thank you for your question regarding the axisymmetric mesh in the bolted joint model. I’d be happy to provide further clarification or discuss this in more detail if needed.

Reasons for Increased Mesh Spacing in This Region:

1. Lower Mechanical Significance

This area is likely:

- Far from stress concentration points (e.g., bolt threads or contact surfaces).

- Not directly affected by applied loads.

- Thus, a fine mesh is unnecessary for analysis accuracy.

2. Computational Efficiency:

-Reducing elements in low-stress regions:

-Speeds up solution time.

-Prevents resource waste.

-Common in "axisymmetric models", where peripheral areas often use coarser meshes.

3. Geometric Constraints

This zone may:

-Belong to a non-critical component (e.g., a washer or flange).

-Serve only to complete the model’s geometry.

4. Smooth Mesh Transition:

-Gradual mesh sizing ensures seamless connectivity between:

-"Fine-meshed" zones (e.g., near bolts).

-"Coarse-meshes" zones, avoiding artificial stress discontinuities.

So

Why Is This a Logical Choice?

-"Sufficient Accuracy": Stresses here are typically uniform and low-impact.

-"Resource Savings": Reduces "70-80%" of unnecessary elements without affecting key results.

Note: If this region includes "boundary conditions" (e.g., supports) or "special loading", remeshing may be needed.

Best regards,

Armin barzin

This is due to no control assigned to global seeds.