There are 6 learning goals for this portfolio.

Question

Design a device that minimizes the force on a macroscopic object during a collision. (i.e., incorporate the concept that for a given change in momentum, force in the direction of the change in momentum is decreased by increasing the time interval of the collision ; and make use of the principle above so the device has the desired effect of reducing the net force applied to the object by extending the time the force is applied to the object during the collision).
Describe the scientific rationale for choice of materials in a design plan for a device that minimizes the force on a macroscopic object during a collision, and for the structure of the device.
Describe the criteria and constraints, along with the tradeoffs in design solutions that minimize a force on an object during a collision (e.g., constraints: cost, mass, the maximum force applied to the object, and requirements set by society for widely used collision-mitigation devices such as seatbelts, football helmets).
Test and evaluate the device based on its ability to minimize the force on the test object during a collision.
Identify any unanticipated effects or design performance issues exhibited by a device that minimizes the force on a macroscopic object during a collision.
Use the test results to improve the performance of a device that minimizes the force on a macroscopic object during a collision (e.g., extending the impact time, reducing the device mass, and/or considering cost-benefit analysis).

Answer 1

To effectively address the six learning goals for your portfolio project focused on designing a device that minimizes the force on a macroscopic object during a collision, here's a structured approach:

1. Device Design

Goal: Design a device that minimizes the force on a macroscopic object during a collision.

Concept: Utilize the principle of impulse-momentum, which states that the force exerted on an object during a collision is proportional to the change in momentum divided by the time duration over which the collision occurs. Therefore, by increasing the time of the collision, we can reduce the peak force experienced by the object.

Design Idea:

• Crumple Zones: Incorporate deformable structures that absorb energy while extending the time of collision through controlled deformation.
• Airbags: Integrate inflatable air barriers that can expand to decelerate the occupant over a longer period.

2. Scientific Rationale for Material Choice

Goal: Describe the scientific rationale for choice of materials and structure.

• Materials:

  • Foams: Use polymeric foams that compress during impact, distributing forces over a longer time and area.
  • Metals: Implement high-strength aluminum or steel for structural integrity but designed in a way that facilitates crumpling (e.g., through the use of honeycomb architecture).
  • Superelastic Materials: Consider materials like shape memory alloys to allow controlled deformation without permanent damage.

• Structure:

  • A multi-layered design where each layer serves a different purpose: impact absorption, structural integrity, and energy dispersion.
  • Use of geometrically optimized structures (e.g., hexagonal shapes) to maximize energy absorption.

3. Criteria, Constraints, and Tradeoffs

Goal: Identify criteria and constraints, as well as tradeoffs.

• Criteria:

  • Must reduce peak force on an object during a collision.
  • Light weight to avoid adding significant mass to the overall system.
  • Economically feasible for production and maintenance.

• Constraints:

  • Cost: Must stay within a predetermined budget for materials and construction.
  • Mass: Should not exceed the weight limits set for the application (e.g., automotive vs. sports).
  • Compliance with safety regulations.

• Tradeoffs:

  • A lighter material might compromise structural integrity.
  • Higher costs for advanced materials might limit accessibility or mass production.
  • Increased complexity in the design may lead to greater chances of failure in real-world applications.

4. Testing and Evaluation

Goal: Test and evaluate the device based on its effectiveness.

Testing Methodology:

• Conduct drop tests using a standardized weight to simulate collisions.
• Use accelerometers and force sensors to measure the forces experienced by an object during the impact.
• Vary the heights and angles of impact to assess performance under different conditions.

Expected Results: Evaluate the coefficients of impact force reduction and compare with baseline values (without the device).

5. Unanticipated Effects or Design Issues

Goal: Identify unexpected effects or design performance issues.

• Possible Over-deformation: The device may crumple more than anticipated, risking damage to the object it was designed to protect.
• Complexity of manufacturing intricate designs could lead to inconsistencies in performance.
• Possible increases in required maintenance due to wear on components that see frequent deformation.

6. Improvement Based on Test Results

Goal: Use test results to improve device performance.

• Adjust Material Properties: Consider using hybrid materials that can provide both energy absorption and recovery.
• Optimize Design: Modify the geometrical configurations based on performance data to improve force distribution.
• Cost-Benefit Analyses: Evaluate tradeoffs between investing in higher-quality materials vs. the resultant increase in safety and performance benefits.
• Extend the time of impact absorption through design changes that promote more controlled deformation or fluid dynamics (e.g., using hydraulic systems).

By systematically addressing each goal, you can ensure that your portfolio exhibits a comprehensive understanding and a methodical approach to minimizing collision forces on macroscopic objects.

Answer 2

When you have completed the tasks for this portfolio, you will turn in the following materials via the Drop Box at the end of the portfolio lessons:

completed Venn diagram comparing and contrasting the egg helmet to a human helmet
written research on phone case materials
review of the results of the stress test on phone case materials
final review or presentation

Answer 3

To help you prepare the materials for your portfolio related to the tasks you've outlined, here’s a structured approach for each component you need to complete:

1. Venn Diagram Comparing Egg Helmet to Human Helmet

Objective: Create a visual comparison that highlights the similarities and differences between egg helmets and human helmets.

Steps:

• Design the Venn Diagram: Use software (like Microsoft Word, Google Slides, or drawing tools) to create a Venn diagram with two overlapping circles.
• Identify Common Features:
  • Purpose: Both helmets provide protection against impacts.
  • Shape & Structure: Both are generally dome-shaped to disperse forces.
• Differences (left circle for egg helmet, right for human helmet):
  • Material: Egg helmets might have a fragile shell (real eggs) vs. polycarbonate or fiberglass in a human helmet.
  • Rigidity: Human helmets are designed for multiple impacts; eggs are designed for single-use protection.
• Final Diagram: Clearly label each section and consider adding images for visual appeal.

2. Written Research on Phone Case Materials

Objective: Compile a written document that explores various phone case materials, their properties, advantages, and disadvantages.

Outline:

• Introduction: Provide context on the importance of choosing the right material for phone cases.
• Types of Materials:
  • Silicone: Flexible, shock-absorbent, easy to grip.
  • Polycarbonate: Hard, durable, scratch-resistant, good impact resistance.
  • TPU (Thermoplastic Polyurethane): Combines rigidity and flexibility, effective in drops.
  • Leather: Offers a premium aesthetic but less shock absorption.
  • Recycled Materials: Eco-friendly options gaining popularity.
• Comparison: Discuss factors like impact resistance, weight, aesthetics, cost, and environmental impact.
• Conclusion: Summarize key findings and highlight the best materials for specific use cases.

3. Review of the Results of the Stress Test on Phone Case Materials

Objective: Document and analyze the results of your stress tests conducted on various phone case materials.

Outline:

• Methodology: Describe how the stress tests were conducted (e.g., drop tests from specific heights, the use of weights).
• Materials Tested: List the materials you included in the tests (e.g., silicone, polycarbonate, TPU).
• Results: Present the results in a clear format (tables, graphs) showing which materials performed the best based on factors like force absorbed, breakage points, and overall durability.
• Analysis: Discuss the performance of each material, highlighting strengths and weaknesses. Explain any patterns found.
• Conclusion: Provide a final assessment of which materials are most effective for phone case construction based on your tests.

4. Final Review or Presentation

Objective: Prepare a comprehensive final review or presentation that synthesizes all your findings.

Outline:

• Title Slide: Introduce your portfolio project.
• Introduction: A brief overview of the project scope.
• Venn Diagram Section: Display and explain the Venn diagram comparing egg helmets and human helmets.
• Phone Case Materials Research: Summarize findings from your written research with visuals/graphics.
• Stress Test Results: Present your analysis using visual aids (graphs, charts) to illustrate results effectively.
• Conclusion & Recommendations: Summarize key takeaways and suggest preferred materials for helmets and phone cases based on your findings.
• Q&A Slide: Prepare to address questions from your audience if applicable.

Presentation Tool Suggestions:

• PowerPoint or Google Slides: For a slide-based presentation.
• Prezi: For a more dynamic and visually engaging format.
• Canva: For designing visually appealing slides with ease.

Final Tips:

• Editing: Proofread each written component for clarity and grammar.
• Visuals: Incorporate images, diagrams, or charts wherever possible to make your materials engaging.
• Citations: Include references for any research or data referenced in your work to maintain academic integrity.

By following this structured approach, you will create a cohesive and comprehensive portfolio that meets the outlined requirements efficiently. Good luck with your project!