Life-Cycle Assessment and Ski Design Quiz

Engineering Design and Material Selection Lecture 8

• Dr. Tino Stankovic and Prof. Dr. Kristina Shea are the instructors
• The lecture focuses on technical drawing: Dimensioning

Course Schedule

• Week 1: Introduction and Sketching, Case study: Health, Lecturer: Prof. Dr. Kristina Shea
• Week 2: Introducing Engineering Design, Case study: Health, Lecturer: Prof. Dr. Kristina Shea
• Week 3: Technical Drawing: Projections and Cuts, Lecturer: Prof. Dr. Kristina Shea
• Week 4: CAD: Introduction and Modeling Operations, Lecturer: Prof. Dr. Kristina Shea
• Week 5: CAD: Features and Parametric Modeling, Case study: Future Mobility, Lecturer: Dr. Tino Stankovic
• Week 6: CAD: Freeform Modeling, Lecturer: Dr. Tino Stankovic
• Week 7: CAD: Assemblies and Standard Mechanical Parts, Case Study:Health, X (45 min), Lecturer: Dr. Tino Stankovic
• Week 8: Technical Drawing: Dimensioning, Lecturer: Prof. Dr. Kristina Shea
• Week 9: Sustainability in Engineering Design, Lecturer: Prof. Dr. Kristina Shea
• Week 10: Materials and their Properties, Lecturer: Prof. Dr. Kristina Shea
• Week 11: Manufacturing Processes with Focus on Additive Manufacturing, Sustainable Materials, Lecturer: Prof. Dr. Kristina Shea
• Week 12: Material Selection, Lecturer: Prof. Kristina Shea
• Week 13: Review and Q+A, X (75 min), Lecturer: Prof. Kristina Shea

Learning Objectives

• Understand different types of dimensioning and when/where to use them
• Give and read dimensions in technical drawings according to norms
• Give and read simplifications for dimensions
• Dimension special elements (e.g., threads)

3D Model of a Mechanical Ventilator

• A diagram of a 3D model of a mechanical ventilator is shown

Mechanical Ventilator Main Parts and Functions

• Diagrams of the main parts and functions of a ventilator are shown

How should we add dimensions to a drawing?

• Diagrams of a round metal plate with various dimensions are shown

Technical drawing process

• 1: Choose the principal (front) view
• 2: Choose other required views
• 3: Draw the views
• 4: Add dimensions
• 5: Verify

Elements of dimensioning

• Diagrams of leader line, symbol, reference line, indicator of origin, dimension line, terminator, and extension line are shown

Example for Simple Dimensioning

• Illustrations of simple dimensioning on a metal part with measurements are shown. Avoid unnecessary dimensions

Dimensioning for... Function, manufacturing, inspection

• Diagrams linked to function, manufacturing, and inspection are shown

Dimensioning Process

• 1: Define outside dimensions
• 2: Define functional dimensions
• 3: Add required manufacturing dimensions
• 4: Add dimensions for inspection
• 5: Add auxiliary dimensions
• 6: Verify the dimensioning

Functional and Non-Functional Dimensions

• Diagrams of functional and non-functional dimensions on a bolt are shown

Rules for Dimensioning

• Diagrams showing rules for dimensioning on a square metal block, including specified measurements and an Ø8 diameter

How many dimensions have to be added for the dimensioning to be complete?

• A diagram is shown with 4 missing dimensions

Auxiliary Dimensions

• A diagram depicting auxiliary dimensions on a cylindrical metal part

First Example: Cover Plate

• Illustrative example of a cover plate design with related parts and measurements

Cover plate: functional dimensions

• Diagrams/measurements of cover plate with functional dimensions shown

Cover plate: outside dimensions

• Diagram showing outside dimensions of a round cover plate

Cover plate: functional dimensions

• Diagrams showing functional dimensions of the cover plate

Cover plate: manufacturing dimensions

• Diagram depicting manufacturing dimensions of the cover plate

Orientation of Dimensional Values

• A circle divided into sectors displaying dimensional values with angular measurements

Second example: motor holding plate

• Illustration showing a motor holding plate with its components (motor, housing, holding plate)

Motor holding plate: outside dimensions

• Diagrams and measurements of the motor holding plate, including A and B dimensions

Motor holding plate: functional dimensions

• Diagrams showing functional dimensions for the motor holding plate

Motor holding plate: manufacturing dimensions

• Diagrams and measurements of the motor holding plate, with measurements (e.g., A and B, and radii, angles, etc.)

Dimensioning of Special Elements: Bevels and countersinks

• Diagrams showing ways to dimension bevels and countersinks

Arrangement of Dimensions: Chain and Parallel Dimensioning

• Diagrams of chain and parallel dimensioning

Arrangement of Dimensions: Combined Dimensioning

• Diagram showing the combined dimensioning of different components

Arrangement of Dimensions for Internal and External Dimensions

• Diagram concerning internal and external dimensions for a component with measurements

Representation of Internal Threads

• Diagrams showing major and minor dimensions of an internal thread

Representation of External Threads

• Diagram showing major and minor dimensions of an external thread

Representation of Thread Run-Outs

• Diagram showing root and depth of a thread run-out

Connection of Threaded Parts - Hatching

• Diagrams showing connection of threaded parts

How many threaded holes are there on the shown views?

• Multiple images/diagrams in a column showing holes

Checklist for verifying dimensioning

• Several questions regarding dimensioning for verification

Checklist for verifying your technical drawings

• Multiple questions for checking and verifying the quality and correctness of the technical drawings

Drawing comparison 1

• Comparison of a couple of technical drawings, highlighting areas of improvement

Drawing comparison 2

• Comparison of two different technical drawings presented in graphical format

Which drawing is better?

• Comparison of two technical drawings

Case Study Mechanical Ventilator – Wrap-Up

• Diagram/ illustration of the several phases of a mechanical ventilator design (phase 0 - planning, Phase 1-concept development, Phase 2-system-level design, Phase 3-detail design, Phase 4-testing and refinement, Phase 5-production ramp-up), with notes/labels regarding the phases

Dimensioning – Wrap Up

• Bullet points regarding dimensioning of parts, and how it ensures function, manufacturing, and inspection
• The norms define how dimensions are placed and dimensions of drawings
• Verifying and validating drawings
• Using CAD tools

Exercise 8: CAD Drafting

• Details about a linear guide drawing from a 3D model. Create an unambiguous drawing

Environmental Impacts

• Images representing global warming, resource depletion, solid waste, water pollution, air pollution, and land degradation

Global Warming

• The radiation balance keeps the Earth's temperature in equilibrium
• Human activities are generating additional greenhouse gases (like CO2) in the atmosphere.
• The additional radiation increases the temperature
• Sea level, local climates, and ecosystems are very sensitive to temperature increase
• Global warming should be limited to +1.5°C compared to pre-industrial times

Global Warming

• Indicative carbon budget for 2050: 2 tons CO2 eq. / year / person
• Average carbon emissions: Switzerland: 12 t CO2 eq. / year / person; World: 4 t CO2 eq. / year / person
• ETH Goal: Net Zero for 2030
• Avoid, reduce, and compensate

"Doughnut Economics"

• Societal well-being is important for sustainability
• The center of the doughnut represents shortfall for people (e.g., adequate resources)
• The outside represents ecological overshoot (e.g., environmental damage)
• The goal is to operate "in the green" (balance human needs with environmental constraints)

Definition: Sustainable Development

• Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (“UN Commission on Environment and Development”, 1983)

"Conditions" for Sustainability

• Consider the earth as a closed system with limited solar input and natural bio-cycles
• Resources must be used in balance with the rate at which the Earth creates them (including fossil fuels)
• Toxic wastes, heavy metals, radiation, and other “molecular garbage” must be eliminated

Product Life Cycle

• Diagram showing materials, manufacturing, transport, use, and end of life (disposal)

Circular Economy

• A systems solution framework that tackles global challenges like climate change, biodiversity loss, waste, and pollution.
• Aims to be regenerative in terms of material and energy consumption

Manufacturing and Circularity

• Diagram showing primary and secondary manufacturing processes, with a focus on circular economy principles (e.g., sourcing, preparation, feedstock creation, forming, finishing, assembling, disassembly, reusing, repairing)

Circular Economy – 9R Framework

• Strategies for a circular economy, involving refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle, and recover

Stokke Tripp Trapp Chair

• Design for a chair to grow with the child

Sustainability Aspects of the Kyburz PLUS II

• Maximum part reuse between different models (modular design)
• Use of 1st life parts for manufacturing 2nd life vehicles
• Multi-life concept for batteries (3rd life) and recycling-driven battery design (EMPA)

Freitag Bags

• Freitag bags are made from repurposed materials (e.g., truck tarps, inner tubes, seat belts)

Dunlop Recycled Wellington Boots

• Dunlop Wellington boots are made of recycled PVC, rubber, and polyurethane
• Old wellies are collected, re-ground, and re-manufactured to create new ones

Life-Cycle Assessment (LCA)

• Quantifies environmental impact over a product's life cycle
• Steps in LCA: Goal and Scope, Inventory Analysis, Impact Assessment, Interpretation

Software to assist LCA (Granta EduPack Eco-Audit)

• Three measures for quantifying environmental impact: Mass (kg), Embodied energy (Joules/kg), CO2 (kg/kg)
• Includes sections covering eco-audit, materials, manufacture, transport, use, and disposal

Sustainability properties (Granta EduPack Eco-Audit)

• Factors to consider: Recyclability, biodegradability, CO2 footprint, water usage, and energy consumption, including data for stainless steel.

Assessments: CO2 and Energy (Granta EduPack)

• CO2 footprint (kg CO₂e/kg): CO2-equivalent mass of greenhouse gases emitted
• Energy (Joules/kg): Energy required for 1 kg of material
• Distinction between life-cycle phases: Material, manufacture, transport, use, disposal

Example: PET bottle

• Diagram and measurements of a standard PET bottle and its use, which includes molding, filling, transportation, refrigeration, and recycling

Approximate Values for the Energy Use in Each Phase (without Disposal)

• Energy breakdown for civil aircraft, family car, appliances, multi-storey car park, and private house

Which "Eco Audit" (CO2) corresponds to the electric car (CO2)?

• Multiple diagrams of CO2 emissions per product, relating to an internal combustion and electric car

Design for Environment (DFE)

• Minimizes or eliminates environmental impacts of a product over its life cycle
• Maintains/improves product quality and cost while reducing environmental impacts
• Integrates social-ecological aspects with conventional design factors (form, function, costs)
• Expands beyond production and distribution to a closed-loop life cycle (recycling)

Four Simple DFE Rules

• DFE design principles
• Use of recyclable and natural materials
• Elimination of unnatural or toxic materials
• Use of clean, renewable energy sources

DFE in the Engineering Design Process

• Diagram showing phases in the DFE process: Planning, Concept development, System-Level design, Detail design, Testing and Refinement, Production Ramp-up

DFE Process

• A multi-step process for implementing DFE: DFE agenda, identifying potential environmental impacts, selecting material guidelines, applying guidelines, assessing environmental impact, comparing to DFE goals, and refining design decisions/solutions

DFE and Material Guidelines

• Guidelines for sustainable material selection and use
• Avoid combining incompatible materials
• Properly label components, enable material separation for recycling
• Minimizing packaging and weight

Reduce Weight - Substitution of Materials in an Automobile Bumper

• Reduction of weight and associated energy requirements from a case study of a bumper replacement
• Using different materials (steel, aluminum, CFRP)

Practice-Oriented Course Addressing MAVT Grand Challenges

• Exercise topics: low-cost ventilators (health), electric vehicles (future mobility), sustainable skis (sustainable materials)

Case Study: Ski Design

• Example of the steps of designing skis (i.e., phases 0-planning, 1-concept development, 2-system-level design, 3-detail design, 4-testing & refinement, 5-production ramp-up)

Skis – An Engineered Sandwich

• Structure and materials of skis (fibers, wood, laminated structure for top sheet, and base and edges)

Impact of Material Selection on CO2

• Graph illustrating CO2 emissions associated with various ski material selections

LCA of the Skis Made at ETH

• LCA of skis made at ETH, environmental impact analysis, and comparison with industry standard, highlighting waste production analysis

LCA of the Skis Made at ETH – Reality Check

• Analysis of the carbon footprint (CO2) from producing and using skis, compared to factors like car travel distances/emissions, and transportation

Sustainability in Engineering Design – Wrap Up

• Summary of DFE and Sustainable Development, emphasizing DFE as a crucial component impacting the environmental lifecycle.