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Progettazione di Materiali e Processi

Learn about the process of selecting materials through screening, ranking, and shortlisting. Explore material indices, constraints, and objectives in design. Examples of materials indexes and solved problems included.

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Progettazione di Materiali e Processi

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  1. Progettazione diMateriali e Processi Modulo 1 – Lezione 3 Progettazione e selezione di materiali e processi A.A. 2015 – 2016 Vanni Lughi vlughi@units.it

  2. In the previouslecture…

  3. Materials Data Example of materialpropertytable See CES

  4. Materials Data Example of comparisontable See CES

  5. Materials Data Example of single propertygraph See CES

  6. Materials Data Example of two-propertygraph See CES

  7. The selectionprocess Allmaterials Screening: applypropertylimits Innovative choices Ranking: apply material performance indices Subset of materials Shortlisting: applysupporting information Prime candidates Finalselection: applylocalconditions Final material choice

  8. Function – Objectives - Constraints • Implicitfunctions (e.g. tie, beam, shaft, column) • Constraintsoftentranslatetopropertylimits (temperature, conductivity, cost, …) • Some constraints are more complex (e.g. stiffness, strength, etc.) asthey are coupledwithgeometry -> need of a specificobjective • Material indices help unravelsuchcomplexity

  9. Material indices Performance = f (F, G, M) Functionalrequirements Material properties Geometry Ifseparable: Performance = f1(F) f2(G) f3(M) Material index

  10. Material indices Material index: E0.5/ Material index: E/ Function Objective Constraint Tie Beam Shaft Column ….. Minimum cost Max energystorage Minimum weight Min. environmental impact …… Stiffness Strength Fatigueresistance Geometry ….. Material index: /

  11. In thislecture: • Examples of materialsindexes for ties and beams • Example of ranking • Selectionstategy • Examples of screening • Tables of solvedproblems of elasticity etc. • Table of momentum of intertia

  12. Tensile ties Main spar - beam Compression strut Undercarriage- compression E = Young’s modulus = Density = Yield strength Minimum weight design

  13. Structural panels Structural beam Tensile ties Compression strut (column) Cm = Material cost / kg = Density = Yield strength Minimum cost design

  14. Sometimes a single property • Sometimes a combination Either is a material index Constraints Objective minimise mass Stiffness Strength Explore these! Remember this one too! Criteria of excellence: material indices • Material index =combination of material propertiesthat limitperformance

  15. Sometimes a single property • Sometimes a combination Either is a material index Constraints Objective minimise cost Material cost/kg Stiffness Strength Criteria of excellence: material indices • Material index =combination of material propertiesthat limitperformance

  16. Tables

  17. Tables

  18. Tables

  19. Tables

  20. Tables

  21. Tables

  22. Tables

  23. Tables

  24. Tables

  25. 1000 Ceramics Index Composites Increasing M 100 Rearrange: E = ρ2 M2 Woods 10 Take logs: Young’s modulus E, (GPa) Metals Log E = 2 log  + 2 log M 2 1 Polymers 0.1 Function Index Slope Tie 1 Beam 2 Panel 3 Elastomers Foams 0.01 10,000 100,000 1000 100 Density ρ(kg/m3) Ranking, using charts Light stiff beam:

  26. Zoom Un-zoom Add envelopes Add text Cancel selection Black and white chart Box selection tool Grey failed materials Hide failed materials Line selection tool Line selection Enter slope 1 OK Cancel The chart-management tool bar

  27. Search area 1 2 3 Ranked by Index Results 22 pass Material 1 2230 Material 2 2100 Material 3 1950 etc... Optimized selection using charts

  28. 1. Selection data Bar chart of index Edu Level 2: Materials 2. Selection Stages Graph Limit Tree - / ^ ( ) + * • List of properties • Density • Modulus • Yield strength • etc Ranked by Index Results 22 pass Material 1 2230 Material 2 2100 Material 3 1950 etc... Plotting indices as bar charts Tools Select Browse Search ( Modulus ^ 0.5 ) / Density Y-axis X-axis Advanced • List of properties • Density • Modulus • Yield strength • etc

  29. Index Ranked by Index Results 22 pass Material 1 2230 Material 2 2100 Material 3 1950 etc... Plotting indices as functions

  30. Function – Objectives - Constraints • Implicitfunctions (e.g. tie, beam, shaft, column) • Constraintsoftentranslatetopropertylimits (temperature, conductivity, cost, …) • Some constraints are more complex (e.g. stiffness, strength, etc.) asthey are coupledwithgeometry -> need of a specificobjective • Material indices help unravelsuchcomplexity

  31. Search Browse Select Tools 1. Selection data Choice… Select from Level 2: Materials 2. Selection Stages Graph Limit Tree Custom Define your own subset Edu Level 1 Materials Processes ….. Edu Level 2 Materials Materials with Durability props Materials with Eco properties Processes ….. Plotting and selection tools CES Selection Toolbox

  32. General properties Limit Mechanical propertiesMin. Max. Glasses 100 50 70 16 Young’s modulus GPa Yield strength MPa Hardness Vickers Fracture toughness MPa.m1/2 Ceramics Metals Foams Polymers Thermal propertiesMin. Max. 0.1 1 10 100 200 1 10 1600 Max service temp C T-conductivity W/m.K T-expansion 10-6/C Specific heat J/kg.K Insulator Thermal conductivity (W/m.K) Conductor Results X out of 100 pass Ranking Prop 1 Prop 2 Material 1 2230 113 Material 2 2100 300 Material 3 1950 5.6 etc... Electrical properties Eco properties Screening with a LIMIT STAGE

  33. Graph Bar chart Box selection tool Line/gradient selection tool Property Line selection Enter slope 1 OK Cancel Bubble chart Results X out of 100 pass Ranking Prop 1 Prop 2 1 Material 1 2230 113 Material 2 2100 300 Material 3 1950 5.6 etc... Property 2 Property 1 Screening with a GRAPH STAGE

  34. Tree Trees Materials Universe Process Universe Materials that can be die-cast Material Universe Ceramics and glasses Hybrids: composites Process Universe Results X out of 100 pass + Metals and alloys Selected records Joining + Polymers and elastomers Shaping Material 1 Material 2 Material 3 etc... + Surface treatment + + + + Screening with a TREE STAGE - Die casting Shaping – Die casting

  35. The database References data-table DATA FOR • Metals & alloys • Polymers • Ceramics & glasses • Hybrids DATA FOR • Joining • Shaping • Surface treatment Links Materials data-table Processes data-table Suppliers data-table Select on links Organizing information: the CES Edu database

  36. Translation Constraints • Transparent - of optical quality • Tough – high fracture toughness • Able to be molded Design requirement Protective visor for law enforcers Young’s modulus GPa Yield strength MPa Fracture toughnessMPa.m1/2 Plus graph stage Limit stage Mech. propertiesMin. Max. Optical properties. Transparency ? ? Opaque Translucent Transparent Optical quality Materials for riot shields Best choice: Polycarbonate

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