Optimal Beam Design Project

Term project in Materials and Manufacturing Processes - CFRP-Woodrock composite beam design and testing

Overview

As part of the Materials and Manufacturing Processes course (Team 11), we designed, fabricated, and tested a CFRP-Woodrock composite beam under a 3-point bending test.
The project focused on addressing the challenges of discontinuous layers, voids in lamination, and low stiffness of the foam core.

Idea Formulation

  • Initial design made the center thicker to withstand concentrated loads.
  • Observed issue: carbon remained intact while the foam (Woodrock) was crushed.
  • Proposed a triple-I beam design:
    • Allows CFRP to behave as a single continuum.
    • Stronger against torsion than a standard I-beam.
    • Lamination process simplified, while void formation minimized through careful alignment.

Advantages and Limitations

Advantages

  1. Strong resistance against lateral bending
  2. Better load distribution across the structure
  3. Enhanced global rigidity

Limitation

  • Buckling risk identified, mitigated by using Woodrock reinforcement between webs

Theoretical Analysis

Process and Analysis

  • Manufacturing: Laminated and bonded CFRP with Woodrock, emphasizing vertical alignment to reduce voids.
  • Simulation: Performed SolidWorks stress analysis to estimate maximum load capacity, accounting for stress concentration.
  • Testing: Conducted 3-point bending experiments and compared results with theoretical and simulation predictions.

Outcomes

  • The fabricated beam (178 g) successfully withstood the maximum allowed load of about 140 kg without failure.
  • This was the highest load-bearing result among all 16 teams, even though the final ranking was 4th place due to scoring criteria.
  • Results validated both the theoretical and simulation predictions, highlighting the effectiveness of the triple-I beam design.

Key Takeaways

  • Learned the importance of void minimization and structural continuity in composite design.
  • Experienced the full cycle of design, simulation, fabrication, and testing.
  • Gained practical skills in teamwork, composite material handling, and stress analysis.