Selecting materials at an early product design stage tools and methods

Transcription

1 ENGINEERING DESIGN Selecting materials at an early product ROUNDTABLES March 17, 2015 Selecting materials at an early product design stage tools and methods Arlindo Silva et al. Instituto Superior Tecnico University of Lisbon, Portugal March 17, 2015 Instituto Superior Técnico 1

2 Outline The materials selection problem Materials screening: an example on natural fiber composites Optimization: an example from the automotive industry Integration: an example from the aeronautics industry Conclusions and final remarks March 17, 2015 Instituto Superior Técnico 2

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7 The materials selection problem Innovation requires innovative thinking and new applications for new (or old) materials Today, a designer can pick between ~160,000 different materials But how? March 17, 2015 Instituto Superior Técnico 7

8 Structured methods are mostly in use (Ashby procedure, MADM, whatever worked before, ) This presentation will be about MADM March 17, 2015 Instituto Superior Técnico 8

9 Common themes for the case studies Data Method Visualization The result is never a single material, but a map of possible materials to help the designer make informed decisions March 17, 2015 Instituto Superior Técnico 9

10 Materials screening: an example on natural fiber composites What is the hypothetically best combination of natural fiber and bio-resin for a structural composite panel? Naturally depends on the function but some requirements are pervasive! Specific strength and stiffness, weight, cost, March 17, 2015 Instituto Superior Técnico 10

11 Data, data, data! March 17, 2015 Instituto Superior Técnico 11

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15 What about a composite with 30%V f? March 17, 2015 Instituto Superior Técnico 15

16 Optimization: an example from industry Is optimizing each part of a large set of parts the same as optimizing the set globally? Generally not => look for global optimum Again, the global optimum depends on the requirements for that set of parts March 17, 2015 Instituto Superior Técnico 16

17 Small stampings for automobiles Stiffness or strength enforced at the absolute minimum cost (and/or weight) Take into account: Manufacturability proxies (FLD) Simplified design models Stamping cost models Economies of scale March 17, 2015 Instituto Superior Técnico 17

18 Baseline scenario: Part number Material grade Part Thickness Set of 55 small stampings 36 different steel grades 26 different material thicknesses Come up with an optimized set for weight, manufacturing costs, and materials acquisition costs March 17, 2015 Instituto Superior Técnico 18

19 The procedure: Generate new vector Design model Use Direct Multi Search Optimization Derivative-free Capable of handling the discrete design variables Generate and evaluate alternative sets and build a Pareto front DMS Iterates Accept? Yes Objective function Pareto dominance Pareto front No Baseline solution Technical cost model Material cost model March 17, 2015 Instituto Superior Técnico 19

20 Normalized result Selecting materials at an early product Sets on the Pareto front after X iterations: Man. Cost Acq. cost Set Weight Objective functions March 17, 2015 Instituto Superior Técnico 20

21 Normalized result Selecting materials at an early product Sets on the Pareto front after X iterations: Man. Cost Acq. cost Set Weight Objective functions March 17, 2015 Instituto Superior Técnico 21

22 Integration: an example from the aeronautics industry Selection of composite materials considering cost and environmental factors without neglecting structural performance! March 17, 2015 Instituto Superior Técnico 25

23 Challenge for the designer: Variety of materials per layer Organization of the layers Orientation of each layer # iterations required to meet design requirements March 17, 2015 Instituto Superior Técnico 26

24 Market need Problem Statement Conceptual Preliminary Possible solutions Candidate materials Possible Layups Short list of possible solutions More specific material prop. FE Analysis Detail Working drawings Refined cost estimates Coupon Testing Prototyping *Adapted from Aceves (2008) Production March 17, 2015 Instituto Superior Técnico 27

25 Main Objective of the Research Environmental Performance (Eco Audit Module) Indicators: EI99, total energy consumption, recyclability etc. Material Selection Interface Indicators: stiffness, weight, buckling, crashworthiness etc. Technical Performance (FEM Module) Economic Performance (PBCM Module) Indicators: max. gross margin, min. investment cost etc. March 17, 2015 Instituto Superior Técnico 28

26 FEM Module No Part and Process Description Cost Generate new vector PBCM Module Verify Const s Eco Audit Module Yes Objective Function Calculation Iteration Pareto Dominance Pareto Front

27 new iteration Run DMS DMS Optimizer Objective: min f1(x), min f2(x) Check domina nce f1,f2 Pareto front file (.txt) x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 f1(x) Calculate Fabrication Cost Cost Model (.xlsx) Nastran input file (.bdf) Run Nastran f1(x) = total fabrication cost f2(x) = displacement (R1) x1-x8 = Orientations (0, +45, -45, 90) x9 = Material type (1, 2, 3) x10 = Number of layers (1-8) f2(x) Nastran output file (.f06)

28 Pre-processor: MSC Patran 2014 Solver: MSC Nastran 2014 MODEL DEFINITION: L:1000mm, W:1000mm flat plate The laminate can be up to16 symmetric plies with equal thickness. The plies have four orientations: 0, +45, -45 and 90 degrees. The plate is fixed along one end and supported vertically in one of the other two corners. The plate is loaded with a uniform pressure of 0.1k Pa, giving a total force of 100 Newton on the plate.

29 Flat Plate Material Types # Material Name Desciption Unit Cost Thickness Tensile Modulus Poisson's ratio In-Plane Shear Modulus 1 CC 206 ET % 2 CC 284 ER % 3 CC 600 ET 445 S 38 % PREPREG Carbon/ Epoxy PREPREG Carbon/ Epoxy PREPREG Carbon/ Epoxy 27,87 0, , ,30 0, , ,36 0, ,

30 Mold Production Cutting Lamination Finishing Demolding Curing Reverse Engineering & Quality

31 Displacement (f1) Selecting materials at an early product 5,00 4,00 3,00 2,00 1,00 0, Total Fabrication Cost (f2)

32 Conclusions Selecting materials is a complex, engineering systems problem Its implications in a real context are still not fully grasped Further research with advanced optimization tools can help March 17, 2015 Instituto Superior Técnico 35

33 Credits to: Profs. Mihail Fontul, Elsa Henriques, Marco Leite, Inês Ribeiro and Paulo Peças (IST), and José Madeira (IPL) Dr. Richard Roth (MIT) Dr. Georgios Koronis (former PhD student, IST) Elçin Calado (PhD student, IST) March 17, 2015 Instituto Superior Técnico 36

34 ENGINEERING DESIGN Selecting materials at an early product ROUNDTABLES March 17, 2015 Selecting materials at an early product design stage tools and methods Arlindo Silva et al. Instituto Superior Tecnico University of Lisbon, Portugal March 17, 2015 Instituto Superior Técnico 37