Unformatted text preview: Materials Selection in Mechanical Design by M.F.Ashby M.F.Ashby
AEX4-X04 AEX4-X04 Sybrand van der Zwaag Sybrand Course Structure Course 26-01 Introduction, Design Process, Eng. Materials 26-01 02-02 Material Selection and the Selection Process 09-02 Lecture Cancelled 16-02 Selection of Material and Shape 23-02 Multiple constraints 01-03 Processing and Design 08-03 Data Sources and Forces for Change Aim of the course Aim To provide the student with the To skills to select via systematic and objective procedures the and best material and process in mechanical design issues mechanical To train the students in the use To of such tools. Mechanical Design Mechanical
Mechanical components : - have mass - carry loads carry - conduct heat and electricity - exposed to wear and corrosion - are made of materials - have a shape - must be manufactured Inter- relations Inter- Evolution of Engineering Materials Evolution The Design Process The To develop a methodology for To selecting materials and processes which is design led, design i.e. the design uses as inputs the functional requirements of the design. The design process The A technical system technical A systems approach systems Types of design Types Original design Original Adaptive or development design Variant design Design Methodology Design Function analysis Function How to open a corked bottle ? How Working principles Working Axial force Internal pressure Shear force Function structure and working principles of cork removers principles Realisation Realisation Straight force Lever Spindle Spring Conclusion Conclusion Design is an iterative process It starts with a need statement The a concept is devised An embodiment is envisaged An and detailed and The embodiment is refined on The the basis of ever more refined data data Engineering materials and their properties their Classes of materials Intrinsic or atom related material Intrinsic properties Tailored or microstructure related Tailored properties properties Non-mechanical properties, such as Non-mechanical cost cost Engineering material families Engineering Definition of properties in units Definition Density (kg/m3) Elastic moduli (GPa) Fracture strength (MPa) Resilience (J/m3) Hardness (GPa) Toughness (MPa.m1/2) Loss coefficient (-) Thermal conductivity (W/mK) Shapes of stress strain curves Shapes Material properties (continued) Material Thermal diffusivity (m2/s) Specific heat (J/kg.K) CTE (K-1) Thermal Shock resistance Creep resistance Wear constant (Archard : W/A.P) (Archard Wear Corrosion rate MATERIAL SELECTION CHARTS (bar chart) CHARTS MATERIAL SELECTION CHART (Bubble chart) CHART Material Property Charts Material Recapitulation Recapitulation Design cycles from function Design analysis to embodiment to design design Materials selection on properties A cyclic loop ...
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- Spring '09
- Materials Science, Design Methodology Design, design Variant design, mechanical design issues