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Total Design. Market Assessment. is a systematic activity: Identification of the market need → sale of product to meet that need. Product, Process, People, Organization, etc. Design Core Market Analysis Specification Concept Design Detailed Design Manufacturing Sales
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Total Design Market Assessment • is a systematic activity: • Identification of the market need → sale of product to meet that need. • Product, Process, People, Organization, etc. • Design Core • Market Analysis • Specification • Concept Design • Detailed Design • Manufacturing • Sales • Product Design Specification (PDS) • Envelopes all stages of the design core Specification Concept Design Detail Design Manufacture Sell THE DESIGN CORE
The Design Core Market Assessment Specification DETAIL DESIGN A vast subject. We will concentrate on: Materials Selection Process Selection Cost Breakdown Concept Design Detail Design Manufacture Sell
Metals and Alloys Wire-reinforced cement Cermets MMCs Steel-cord tyres Composites Ceramics and Glasses CFRP GFRP Polymers Filled polymers Materials Selection
STRUCTURAL MATERIALS Physical optical magnetic electrical Mechanical tribology fatigue KIC σy UTS E Chemical corrosion oxidation FUNCTIONALMATERIALS MATERIAL Other feel look Thermal α K H Tm TTransition Environmental recycling energy consumption waste Materials Properties
Generic materials selection Problem statement Model Function, Objective, Constraints Selection Examples Oars Mirrors for large telescopes Low cost building materials Flywheels Springs Safe pressure vessels Precision devices Materials Selection without Shape
Generic Materials Selection p: Performance of component; f(F,G,M) F: Functional requirement, e.g. withstanding a force G: Geometry, e.g. diameter, length etc. M: Materials properties, e.g. E, KIC, ρ Separable function if: P = f1(F) · f2(G) · f3(M) TASK: Maximize f3(M) where M is the “performance index”
Procedure for Deriving “M” • Identify the attribute to be maximized or minimized (weight, cost, energy, stiffness, strength, safety, environmental damage, etc.). • Develop an equation for this attribute in terms of the functional requirements, the geometry, and the material properties ( the objective function). • Identify the free (unspecified) variables. • Identify the constraints; rank them in order of importance. • Develop equations for the constraints (no yield, no fracture, no buckling, maximum heat capacity, cost below target, etc.). • Substitute for the free variables from the constraints into the objective function. • Group the variables into three groups: functional requirements, F, geometry, G, and materials properties, M. • Read off the performance index, expressed as a quantity, M, to be maximized. • Note that a full solution is not necessary in order to identify the material property group.
Guidelines for M = Prop2/Prop1 Search Region M = 40 The Materials Selection Map
Search Region M = 100Nm/g f1(F) f2(G) f3(M) So, to minimize mass m, maximise Example I: A light strong tie
Search Region f1(F)·f2(G)·f3(M) So, to minimize mass m, maximise Example II: A light stiff column (circular)
Light weight cylindrical vessel of fixed radius Search Region f1(F)·f2(G)·f3(M) So, to minimize mass m, maximise Example III: Pressure Vessel
Performance Indices: Elastic Design Note:σf = failure strength; E = Young’s modulus; ρ = density; η= loss coefficient
Performance Indices: Min. Weight Note:σf = failure strength; E = Young’s modulus; G = shear modulus; ρ = density
Performance Indices: Min. Weight Note: KIC = fracture toughness ρ = density
f1(F)·f2(G)·f3(M) So, to minimize mass m, maximise Materials for Large Telescopes
Search Region M = 2 (GPa)1/3m3/Mg Materials for Large Telescopes
Second moment of area: So, to minimize mass m, maximise Materials for Oars
Search Region M = 6 (GPa)1/2m3/Mg Materials for Oars
F b b y σ=σy Materials for Buildings Floor Beam
Search Region Search Region M1 = 1.6 M2 = 6.8 Materials for Buildings
Yield before break Leak before break Minimum strength Materials for Safe Pressure Vessels
M1 = 0.6 m1/2 M3 = 100 MPa Materials for Safe Pressure Vessels Search Region
Energy Stored σ σf ε σf/E Materials for Springs
Search Region M1 = 6 MJ/m3 Materials for Springs
Search Region M2 = 2 kJ/kg Materials for Springs
Kinetic energy: Polar moment of inertia: Mass: Stress: Materials for Flywheels
Search Region M1 = 100 kJ/kg Maximizing energy/volume Materials for Flywheels Maximizing energy/mass
Heat flow : Thermal strain : Materials for Precision Devices
Al Ag Cu Au Be Mo W SiC Si Diamond Search Region M1 = 107 W/m Materials for Precision Devices