Engineering Design Lecture

Introduction to Engineering Design

Course Overview

  • Instructor: Madhu Dilsha, a graduate from the University of Morgula.
  • Course: Engineering Design Module.
  • Contact: Students can reach out with any questions related to the module.

Learning Outcomes

  • Outcome 1: Plan a design solution and prepare engineering design specifications in response to stakeholder needs.
    • Engineers must design solutions to fulfill stakeholder purposes.
    • Stakeholders present problems or requirements needing solutions.
    • Good planning is essential for achieving successful design outcomes.
  • Outcome 2: Formulate possible technical solutions to address design specifications.
    • Students will engage in a small design project within the module.
    • Lectures will cover necessary theories and background knowledge.
    • Assignments will require designing an engineering outcome.
  • Outcome 3: Prepare an industry-standard engineering technical design report.
  • Outcome 4: Present a design solution to an audience based on the design report and evaluate the presentation.

Recommended Books

  • Refer to provided list for recommended books.
  • Lecture materials will reference these textbooks.
  • Students can consult textbooks for questions or contact the instructor directly.

What is Design?

  • Design is not exclusive to engineering; it is present in various fields (aesthetics, architecture, etc.).
  • Design has driven global development and improvements throughout history.
  • Mankind's development is attributed to design improvements from ancient times to the present.
Engineering Design
  • Engineering design is a systematic and precise approach to the design process.
  • It involves a structured methodology rather than random or arbitrary methods.
  • Definition: "Engineering design is the systematic intelligent generation and evolution of specifications for artifacts whose form and function achieve stated objectives and satisfy specified constraints."
  • Artifacts can include machines, effect parts, or theoretical solutions.
  • Designs should address objectives and adhere to specified constraints.

Engineering Design Process

  • Involves analyzing requirements and creating specifications to realize desired objects.
  • Considers both the form/appearance and the function of the design.
Example: Designing a Smartphone
  • Objective: Design a new smartphone that is lightweight and high-performance.
  • Form: Create a durable, lightweight frame, evolving from bulky phones to thin designs (e.g., 2.5mm thin).
  • Functions:
    • Fast processor.
    • Long battery life.
    • High-quality display.
  • Constraints:
    • Cost: Must be affordable for the average consumer.
    • Material Selection: Balancing cost with optimal materials (e.g., titanium alloys).
    • Manufacturing Limitations: Production capabilities limit design possibilities.

Planning Techniques for Engineering Design

  • Good planning is essential for preparing design specifications.
  • Design specifications include dimensions, areas, materials, costs, objectives, and constraints.
  • Time is a critical design specification; designs must be completed within a set timeframe.

Steps for Design Specifications

1. Defining Client/User Objectives
  • Engineers often receive requests from clients who may not have a clear idea of their needs.
  • Understand the client's vision and needs through careful listening and research.
  • Conduct surveys and interviews to identify objectives, especially for new products.
  • Convert abstract ideas into measurable design specifications.
  • Differentiate between essential and desirable features.
  • Align objectives with market needs to ensure product viability and revenue.
Example: Automotive Industry Product Design
  • Clients may present problems from a limited perspective.
  • Engineers must understand all objectives that the client needs to fulfill.
  • Example: Improving the safety of an electric car for disabled people.
    • Measure safety improvements against standards (e.g., NCAP ratings).
    • Conduct tests to obtain ratings and demonstrate enhancements.
    • Quantify improvements (e.g., increase NCAP rating from 3 to 5).
  • Another example: Reducing the weight of a machine while maintaining performance.
    • Quantify the weight reduction target (e.g., reduce weight by 5%).
2. Identifying Needs and Constraints

  • Different types of needs:

    • Functional Needs: Performance requirements (e.g., increased engine horsepower).
      • Engine performance, measured by horsepower increase (e.g., increase by 5 horsepower).
      • Efficiency improvements, measured in percentages (e.g., increase efficiency by 5%).
    • Durability: Improving gear durability through heat treatment.
    • Aesthetic Needs: Design appeal and ergonomics.
      • Ergonomics is the comfort and ease of interaction with machines.

  • Constraints:

    • Technical Constraints:
      • Material properties (e.g., using aluminum with limited shear stress).
      • System integration limitations.
      • Using existing parts and space constraints.
    • Economic Constraints:
      • Budget limitations.
      • Cost-effectiveness: Maximizing output with minimal cost.
    • Environmental Constraints:
      • Minimizing environmental impact.
      • Managing wastewater in chemical plants.
    • Social Constraints:
      • Safety (e.g., steel parts on buses).
      • Ethical considerations (e.g., sound systems respecting others).
    • Budget Limitations:
      • Achieving project goals within a given budget.
      • Finding effective solutions with limited resources.
Design Constraints
  • Focus on design-specific constraints within a larger project.
  • Three-D modeling constraints:
    • Manufacturing feasibility (can the design be manufactured?).
    • Material selection constraints:
      • Strength limitations.
      • Weight restrictions.
      • Cost and availability.
    • Regulatory and safety comments:
      • Adherence to industry standards (e.g., aerospace regulations).
      • Time constraints: Balancing scope, time, and cost to achieve optimal design quality.
3. Functional Specification Development
  • Specifying tasks, key performance indicators (KPIs), and measurable goals.
  • Ensuring reliability and maintainability.
  • Considering economics and usability.
  • Evaluating environmental impact and sustainability.
Key Performance Indicators (KPIs)
  • KPIs are used in industry to describe specific metrics.
  • KPI qualities: relevant, attainable, measurable, specific, and resource-allocated.
    • Example: In aircraft engines, RPM rate or exhaust temperature can indicate performance.
4. Establishing Milestones in Design
  • Creating a work plan and project phases with distinct stages and deadlines.
  • Tracking progress and monitoring development against milestones.
  • Conducting case studies to ensure feasibility in real-world engineering projects.
Example: Development of an Electric Vehicle Prototype
  • Milestones:
    • Concept design approval.
      • Tasks involve defining needs, constraints, and measurable targets.
    • Initial CAD model completion.
      • Combining calculations and theory applications with CAD modeling.
      • Iterative process.
    • Prototype fabrication.
    • Testing and refinement.
    • Final design.

Work Breakdown Structure

  • Task breakdown involves dividing the project into manageable parts.
  • Allocate resources, personnel, and time to each task.
  • Prioritize critical tasks and effectively manage time.
  • Essential for project management and team coordination.
  • Involves assigning responsibility for different tasks to specific teams.
Example: Electric Vehicle Project
  • Different teams responsible for various systems (e.g., brakes, chassis, batteries, electronics).
  • At the end of each milestone, the responsible parties have the deliverables ready.