Major phases of design, effect of material properties on design, effect of manufacturing processes on design. Material selection process- cost per unit property, weighted properties and limits on properties methods. Guidelines for design for manufacturability. Review of relationship between attainable tolerance grades and different machining processes.Processcapability,mean, variance, skewness, kurtosis, process capability indices-Cp, and Cpk.
Cumulative effect of tolerance- Sure fit law and truncated normal law, problems.
Selective Assembly:
Interchangeable part manufacture and selective assembly. Deciding the number of groups -model-1: group tolerance of mating parts equal, model- 2: total and group tolerances of shaft equal. Control of axial play- introducing secondary machining operations, and laminated shims; examples.
True positional theory:
Comparison between coordinate and true position method offeature location. True position tolerance- virtual size concept, floating and fixed fasteners, projected tolerance zone and functional gages. Concept of Zero true position tolerance. Simple problems on true position tolerancing.
Datum Features:
Functional datum, datum for manufacturing, changing the datum;examples.
Component Design:
Design features to facilitate machining: drills, milling cutters, keyways, Doweling procedures, counter sunk screws, Reduction of machined area, simplification by separation, simplification by amalgamation, Design for machinability, Design for economy, Design for clampability, Design for accessibility. Design for assembly
Design of components with casting considerations:
Pattern, mould, and parting line. Cored holes and machined holes. Identifying the possibleand probable parting lines. Castings requiring special sand cores. Designing to obviatesand cores.
Welding considerations:
requirements and rules, redesign of components for welding; case studies.
Forging considerations -requirements and rules-redesign of components for forging and case studies. Design of components for powder metallurgy- requirements and rules-case studies. Design of components for injection moulding- requirements and rules-case studies.
Course outcomes:
1.Describe the different types of manufacturing systems and comparetheir suitability foreconomic production of various components and products.
2.Identify factors and causing mechanisms of the defects likely to occur with different manufacturing processes in producing mechanical products and the relevant design approaches to rectify them.
3.Select proper materials and manufacturing processes for designing products/components by applying the relevant principles for ease and economic production.
TEXT BOOKS:
1. Peck, H. “Designing for Manufacture”, Pitman Publications, London, 1983.
2. Dieter, G.E. “Engineering Design: A Materials and processing Approach”, McGraw Hill Co.Ltd, 2000.
3. Bralla, James G., “Handbook of Products Designfor Manufacturing: A Practical Guide to Low-cost Production”, McGraw Hill, New York, 1986.
REFERENCE BOOKS
1. Eggert, R.J. “Engineering Design” Pearson Education, Inc., New Jersey, 2005.
2. Matousek , R. “Engineering Design”, Blackie and Son Limited, Glasgow, 1967.
3. KalandarSaheb, S.D and Prabhakar, O. “Engineering Design for Manufacture”,ISPE 1999.
4. Trucks, H.E., “Design for Economical Production”, 2nded., Mich., Dearborn, SME 1987.
5. Linberg, Roy A., “Processes and Materials of Manufacture”, 4thed.,Allyn and Bacon, Boston, U.S.A., 1990.