Executive summary

This project investigates the structural performance and weight optimization of a steel cylindrical support subjected to a static bearing load. Using ANSYS Workbench, finite element analysis (FEA) and response surface‑based optimization are applied to study how web thickness influences von Mises stress and total mass. The goal is to achieve a safe, lightweight design that satisfies stress constraints while minimizing material usage.

Objective

Design goal:

• Minimize mass of the cylindrical support.

• Maintain safety by keeping maximum von Mises stress ≤ 35 MPa (±1 MPa tolerance).

Key design variable:

• Web thickness of the middle cylinder.

Loading condition:

• 12 kN bearing load applied on the central cylinder.

Theory and methodology

Finite element analysis (FEA):

• Material: steel, , .

• Geometry: three connected cylinders with an internal web.

• Mesh: 6 mm element size to capture stress and deformation accurately.

• Boundary conditions: outer cylinders fixed in radial and axial directions; middle cylinder loaded with 12 kN bearing load.

Initial static analysis:

• Max von Mises stress: 38.805 MPa

• Max total deformation: 0.023882 mm

• Mass: 22.413 kg 

This baseline design is structurally safe but exceeds the target stress limit, motivating optimization of web thickness.

Design of experiments and response surface

Parameterization:

• Input: web thickness

• Outputs: maximum von Mises stress, total mass

DOE setup:

• Central Composite Design (CCD)

• Thickness range: 16 mm ≤ t ≤ 36 mm

• Multiple design points automatically generated in ANSYS Workbench.

Response surface modeling:

• Second‑order polynomial fit for stress and mass.

• Used to predict performance across the full thickness range and support optimization.

Optimization and trade‑off analysis

Optimization setup:

• Objective: minimize total mass.

• Constraint: maximum von Mises stress ≤ 35 MPa (±1 MPa).

• Method: screening‑based optimization with 1000 samples and 3 candidate points.

The study reveals a clear trade‑off:

• Increasing thickness reduces stress but increases mass.

• Decreasing thickness reduces mass but pushes stress above the allowable limit.

Three candidate designs on the Pareto front were identified, balancing stress and mass. Candidate Point 3, with a thickness of 24.25 mm, achieves a maximum stress of 33.163 MPa and a mass of 23.376 kg, making it the most favourable design solution under the given constraints.

Conclusion

“The finite element and optimization study of the cylindrical support structure provided valuable insights into the trade-off between web thickness, structural mass, and stress performance.”

The analysis confirms that modest increases in web thickness can yield structurally sound configurations under the applied 12 kN bearing load, while still maintaining reasonable mass. Candidate Point 3 (24.25 mm web thickness) represents the optimal balance between safety and efficiency, demonstrating the effectiveness of simulation‑driven design and response surface optimization in structural engineering.

Future work may explore additional geometric changes, alternative loading scenarios, or multi‑objective optimization to further refine performance.