1 Views using first angle projection; used in Europe. Views using third angle projection; used in North America DRAWINGS

2 Customary views using first angle projection DRAWINGS

3 Customary views using third angle projection bracket 01.sldprt DRAWINGS

4 Automatic dimensions are most often not acceptable DRAWINGS

5 Dimensions must either modified or created DRAWINGS

6 first third angle EXAMPLE part.sldprt

7

8

9 Automatic dimensions are most often not acceptable DRAWINGS

10 Dimensions must either modified or created DRAWINGS

11 DRAWINGS BOM TOC

12 DRAWINGS Learn to use all types of views in drawings Learn BOM Learn TOC Learn dimensioning … Learn fits and GD&T; we’ll cover this later in the course

13 DESIGN FOR MANUFACTURING PROCESS MATERIAL SELECTION

14 Concurrent* Engineering Using DFM [Bakerjian 1992] Design concept Design for Assembly (DFA) Selection of materials and processes; early cost estimates Best design concept Design for manufacture (DFM) Prototype Production Suggestions for simplification of product structure Suggestions for more economic materials and processes Detail design for minimum manufacturing costs We are here *Concurrent: Occurring or operating at the same time; "a series of coincident events".

15 Factors that Influence Manufacturing Process Selection Cost of manufacture Material Geometric shape Tolerances Surface finish Quantity of pieces required Tooling, jigs, and fixtures Gages Avaliable equipment Delivery date

16 Materials and Manufacturing In many manufacturing operations the cost of materials may account for more than 50% of the total cost automobiles :70% of manufacturing cost shipbuilding :45% of manufacturing cost Note: The higher the degree of automation (lower labor costs), the greater the % of the total cost is due to materials. Variety of Materials in a Product

17 Most Commonly Used Materials Steels and Irons S30400 (stainless) 6.S316 (stainless) 7.O1 tool steel 8.Grey cast iron Aluminum and copper or C268 (copper) Other metals 14.Titanium Magnesium AZ63A Plastics 16.ABS 17.Polycarbonate 18.Nylon 6/6 19.Polypropylene 20.Polystyrene Ceramics 21.Alumina 22.Graphite Composite materials 23.Douglas fir (wood) 24.Fiberglass 25.Graphite/epoxy

18 Performance Characteristics of Materials The performance requirements of a material are expressed in terms of physical, mechanical, thermal, electrical, or chemical properties. Characteristics of Material Classes MetalsCeramicsPolymers StrongStrongStrong StiffStiffCompliant ToughBrittleDurable Electrically conductingElectrical insulatingElectrically insulating High thermal conductivityLow thermal conductivityTemperature sensitive

19 Materials Used in Common Items [Ullman 1992]

20 Materials Used in Common Items

21 SUMMARY OF IMPORTANT MATERIAL PROPERTIES Modulus of elasticityMPa Poisson’s ratio1 Yield strength (stress)MPa Ultimate strength (stress)MPa Elongation% HardnessHB, HV, … Melting temperatureK Thermal expansion%/ K Thermal conductivityW/(m K) Densitykg/m 3 Cost/unit of mass$ / kg Cost/volume$ / m 3

22 K IC plane strain fracture toughness K ISCC threshold stress intensity factor FAILURE MODES AND MATERIAL PROPERTIES

23 Thomas Young ( ) Modulus of Elasticity

24 Modulus of Elasticity Stress-Strain Relations Steel Aluminum Wood Strain Stress Young's Modulus of Elasticity is a "measure of stiffness" and is high for metals and low for plastics and rubber. The Modulus of elasticity is the stress caused by 100% strain which is doubling the length of a tensile sample (even though most materials would not survive this test)

25 Approximate Moduli of Elasticity of Various Solids Material Young's modulus E [GPa] Young's modulus E [psi] Rubber (small strain) ,500-15,000 Low density polyethylene0.230,000 Polypropylene , ,000 Polyethylene terephthalate , ,000 Polystyrene , ,000 Nylon2-4290, ,000 Oak wood (along grain)111,600,000 High-strength concrete (under compression)304,350,000 Magnesium metal456,500,000 Aluminum alloy6910,000,000 Glass (all types)7210,400,000 Brass and bronze ,000,000 Titanium (Ti) ,000,000-17,500,000 Carbon fiber reinforced plastic (unidirectional, along grain) 15021,800,000 Wrought iron and steel ,000,000 Tungsten (W) ,000,000-59,500,000 Silicon carbide (SiC)45065,000,000 Tungsten carbide (WC) ,000,000-94,000,000 Single Carbon nanotube [1][1]approx. 1,000approx. 145,000,000 Diamond1,050-1,200150,000, ,000,000

26 Approximate Moduli of Elasticity of Various Solids

27 Stress-Strain Curves Yield Strength ( or Yield Stress ) - Stress at which a permanent deformation has occurred Tensile Strength -The maximum nominal stress a specimen supports in a tension test prior to failure. Nominal Stress -Approximate value of stress calculated using the original area A o or length L o ( instead of the actual values which change during testing ). Stress-strain curves illustrating the meaning of yield strength and tensile strength for two types of deformational behavior (steel and polyethylene).

28 STRAIN STRESS Linear material model Non linear material model The linear material behavior complies with Hooke’s law:  =  Ein tension  =  Gin shear  normal stress[ N / m 2 ]  strain[ 1 ]  shear angle[rad] Emodulus of elasticity[ N / m 2 ] Gshear modulus[ N / m 2 ] Linear range Linear vs. nonlinear material models α tanα = E

29 Simeon Poisson (1781 – 1840) Poisson’s ratio

30 When a sample of material is stretched in one direction, it tends to get thinner in the other two directions. Poisson's ratio (ν), named after Simeon Poisson, is a measure of this tendency. It is defined as the ratio of the strain in the direction of the applied load to the strain normal to the load. For a perfectly incompressible material, the Poisson's ratio would be exactly 0.5. Most practical engineering materials have ν between 0.0 and 0.5. Cork is close to 0.0, most steels are around 0.3, and rubber is almost 0.5. Poisson’s ratio

31 Yield Strength [Ullman 1992]

32 Tensile Strength

33 Elongation ( or Plastic Strain ) - Strains that go beyond the elastic limit and result in residual strains after unloading are called inelastic or plastic strains. Elongation

34 Elongation

35 Scratch hardness Primarily used in mineralogy. Indentation hardness Primarily used in metallurgy, indentation hardness seeks to characterise a material's resistance to permanent, and in particular plastic, deformation. It is usually measured by loading an indenter of specified geometry onto the material and measuring the dimensions of the resulting indentation. There are several alternative definitions of indentation hardness, the most common of which are: Brinell hardness test (HB) Janka hardness, used for wood Knoop hardness test (HK) or micro hardness test, for measurement over small areas Meyer hardness test Rockwell hardness test (HR), principally used in the USA Shore hardness, used for polymers Vickers hardness test (HV), has one of the widest scales There is, in general, no simple relationship between the results of different hardness tests. Though there are practical conversion tables for hard steels, for example, some materials show qualitatively different behavior under the various measurement methods. Rebound hardness Also known as dynamic or absolute hardness, rebound hardness measures the height of rebound of an indenter dropped onto a material using an instrument known as a scleroscope Hardness σ TS = 500 x HB

36 Hardness

37 Endurance (Fatigue) Limit Endurance Limit – is a limiting value of stress such that fatigue failure does not occur regardless of the number of cycles of loading ( i.e. the maximum repetitive stress a material can with stand without fracturing ) Fatigue Data for a Composite Note: This composite is fiberglass embedded in phenolic resin.

38 Endurance (Fatigue) Limit

39 Melting Temperature

40 Thermal Conductivity and Thermal Expansion

41 Thermal Conductivity

42 Coefficient of Thermal Expansion

43 Density

44 Cost per units of mass

45 Cost per Volume

46 TYPICAL STEELS AND ALUMINUM ALLOYS USED FOR WELDMENTS AND SHEET METAL Steel sheets Structural steels – tubes1018 Structural Steel Beams - I-beam and channel1018? Steels - Hot and cold rolled bars1010? Steel shafts/rods1010, 1045 Aluminum Sheets6061, 6065 (not bendable without heat) 3003 (utility grade- great for bending, machines very poorly-sticky and clogs cutters) 1000 series (poor quality aluminum, good for bending) Aluminum shapes and beamsT6061 (T designates temper) Aluminum billets, bars and rodsT6061, T7075 (T designates temper). Both have good machine-ability machines better and will polish better too.

47 MATERIAL SELECTION Materials selection is based on material properties (part performance) and material processing (part manufacturing). Most material selection is based on past experiences (but doesn't necessarily produce optimal solutions). There are a large number of materials available (eg. over 40,000 metallic alloys alone). An improperly chosen material can lead to: failure of the part or component unnecessary costs

48 BASIC STEPS IN MATERIALS SELECTION 1.Analyze material requirements - determine the conditions of service and environment that the product must withstand. 2.Screen candidate materials - compare the needed properties with a large materials property data-base to select the most promising materials for the application. 3.Select candidate materials - analyze candidate materials in terms of trade -offs of: product performance, cost, fabrication, availability, etc.. 4.Develop design data – if necessary, determine experimentally the key material properties for the selected material to obtain statistically reliable measures of the material performance under specific conditions expected to be encountered in service.

49 Problem: Select a material suitable for designing the core of an automobile radiator. Material Performance Requirements: ( What the material should do) Rapid Heat Transfer Does not melt Does not deform Long lasting Light Weight Inexpensive EXAMPLE OF MATERIAL SELECTION

50 To find out which material properties really matter EXAMPLE OF MATERIAL SELECTION

51 To find out which material will be the best from the point of view of the required properties (decision matrix) EXAMPLE OF MATERIAL SELECTION