Design Engineering

Design Engineering Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Design Visualisation • Purpose is communication. • Converts invisible to the visible. • Includes • 1. two dimentional design drawings. • 2.three dimentional soft modelling • 3.solid modelling. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Design Drawings • Used to communicate to the client • 1.Layout drawings( Show key components, connections, locations..) • 2.Detailed drawings ( Show different components of a device, their connections) • 3.Assembly drawings.( show individual parts or components) Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Layout drawings Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Detailed drawings Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Assembly drawings Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

3D Soft models • Has the capacity to virtually build sites, structures, products faster than 2D drawings. • No space for ambiguity. • Gives precise image. • Advantages • 1. Speed. • 2.Precision & control. • 3.Scenario Virtualization. • 4.Reduced Lead Times. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Solid Modelling • Two techniques • 1. Constructive Solid geometry & Boundary representations. • Done by joining shapes like cube, spheres, cylinder… Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Solid Modelling Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Tolerencing • Not possible to manufacture component to given dimensions ( Slight variations). • Allowable difference of dimensions • Needed to know how much a component can differ from its specifications. • If exceeded the component will no longer function as planned. • Expreseed in 2 ways • 1.Bilateral tolerance ( +/-), 5.00+/-.005m • 2. Unilateral tolerance ( 7.00 + .007 m. • Gives flexibility. • Size, position, location,orientation. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Material Selection • In appropriately selected material can lead to failure • Common scene – contarctors in construction tries to save material / use low quality materials. • Results in failure of construction. • Points in selecting material • 1.have the correct properties. • 2. capacity to molded to finished parts. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Steps in material selection • 1. Analysis of the material requirements.( Purpose should be served) • 2.Screening of candidate materials. ( out of options best may be seen) • 3.Selection of candidate materials ( based on your requirements). • 4.Development of design data based on the materials ( once the material is finalized appropriate standards & specifications have to be used related to the material.) Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Use of standard items in Design. • Arose from the beginning of industrial revolution. • Founding father is Henry Moudslay. • Standards ensure minimum safety & performance. • In design it shows permissible levels of technical details Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

How are Standards Established? • Standards Developing Organisation ( SDO). • Standards Setting Organisation ( SSO). • 1901 first national standard body was founded & named as British Engineering Standards committee. • 1918 it is expanded as British Engineering Standards Association. • 1931 renamed as British Standards Institution. • ANSI- American National Standards Institute. • BIS – Bureau of Indian Standards. • W3C- World wide web consortium. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Research needs in design • Helps to reduce blunders done by others. • Research must be done in • 1.Users to customers. • Research on Products target audience. • 2.Existing Solutions. • Research should be conducted on products that already exists similar to the one you are planning to design Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Research must be done to.. • How the product will work? • How to prepare the product? • To find the best material to work. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Energy Needs In Design • Determining the energy related design needs by observing the proper use & reuse of energy • For green building the energy use should be less than 40 % of the baseline of the energy use. Renewable energy usage should allow for a minimum of 50 % of building energy use. Vacant roof tops allow establishment of renewable energy technologies. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Quadruped Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Lexus LC 500 Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Prototyping • A prototype is an early sample, model, or release of a product built to test a concept or process or to act as a thing to be replicated or learned from. • Used to communicate our ideas with the client. • First Step is Sketching & drawing. • Another tool is 3 D representation. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

3 D representation can be used as • 1. Input to a computational modeling program to simulate the designs performance under specified conditions. • 2. As an input to a variety of rapid prototyping technologies.( as 3D printing). • 3.To generate detailed enginerring drawings of the design. • 4.To Guide the tool path in computer numerical controlled machining. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Prototypes are original models on which something is patterned. • A Model is a miniature representation of something. • Models are usually smaller. • Difference Between Model & Prototype ? • Prototypes are intended to demonstrate that a product will function as designed. • So they are tested in actual operating environments. • Models are tested in controlled environments. • Boeing 747 as a model- small Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Need for prototypes • enable ideas to be tested through trial & error method. • Helps develop procedures for manufacturing process. • Helps to detect errors • Demonstrate new products to customers. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Rapid prototyping • When there is no model in company to tap the information in customers mind. • Company develop prototype model. • Is an incomplete model. • Represents the key parts of the system. • Simple • Inexpensive. • Use CAD ( computer aided design). Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Reasons for rapid prototyping • To increase effective communication. • Decrease development time. • Decrease costly mistakes. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Methods for Rapid prototyping • 1. Create a CAD Model • 2. Convert CAD to the STL (stereolithography) file format . • ( the surfaces of the component are converted into very small triangular facets by process called tesselation) • 3.Slice the STL into thin layers • ( because RP process build up the solid body layer by layer). • 4.Making the prototype • ( first layer is created, & process is repeated until completion of the model) • 5.Post –processing ( surface of the model is finished & cleaned). Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Applications • Automotive • Aerospace. • Medical • Consumer products industries. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Limitations • Still in developing stage only. • Doesnot offer good surface finish. • Machines are very costly. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Testing & Evaluvation. • Prototypes are tested before launched into market. • For many consumer products there is a set of acceptance tests. • Test Plan – description of types of tests to be performed. • when the test is to be made. • costs of tests. • All managers & engineers should be informed of the test plan. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Test Plan contains • Types of tests. • Testing of design prototypes. • Modelling & simulations. • Testing of all mechanical Modes & electrical modes. • Evaluvating the sueful life of critical to quality components. • Testing at specification extremes of temperature,pressure humidity. • Evaluvate all human interfaces with actual users. • Safety & risk test. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Consideration for testing & evaluvation of design • List of important attributes to be tested. • Set of experiments that test those attributes. • Testing conditions.( under controlled conditions,or in working environment). • Recording of test data. • Analysis & comparison of test data with design specifications. • Identify major areas of concern for any redesign work. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Why testing & evaluvation is needed. • To assess the feasibility of design. • To identify potential errors. • To identify safety issues • Conformance to the government standards. • To scrutinize costs. • Evaluate the manufacturing process. • For providing user instructions. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Freezing the Design • Designs are evaluvated & setbacks seen in design is improved by alternative design. • Modified designs are again tested till satisfactory result are seen. • Frozen design are improved further based on customer feedback. • Freezes mark the end point of development stage. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Types of Freezes • 1.External Conceptual freezes- • arise from customer requirements or tooling constraints. • 2.External detailed freezes- • include detailed customer specifications, lead times & use of predefined parts like platform parts • 3.Internal conceptual freezes- • reflect the fundamental decisions made about the concept of the design through out the iterative refinement of the product. • 4. Internal detailed freezes- • occur when components are frozen any time through out the design process. • Is a method of structuring the design process. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Cost Management • Amount of expenditure. • Objective is Low Cost • Method: Estimate Labour, Material, Overhead Cost • Labour: • taking & filling, packing,shipping, insurance, retirements benefits. • Material: • Items & inputs directly used in building the service. • tool used is bill of materials. • Overhead : • not specifically or directly associated with the production of goods & services. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Cost Accounting- • is the process of calculating the cost of an article as a basis to fix its selling price. • Cost Centre is defined as a location where costs are accumulated. • Cost unit – • is the physical measurement. Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Steps in process of establishing cost. • 1. collection of expenditure. • 2.classification of expenditure as per cost elements,function etc.. • 3.Allocation of expenditure to cost centers Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Elements of cost Ladder • Material Cost • A) Direct – one which is used directly to the completion of the product. • Eg. Fc, Ni in alloy steel • B) Indirect- not directly used • Eg. Cotton waste, greases. • Labour Cost. • A) Direct – converts directly the material into saleable products. • Wages paid to workers. • B) Indirect- the workers in factory who help direct workers in connection with their work with regard to supply of materials, power etc..( supervision, mainatinance) Design Engineering-KTU Syllabus- Module 3- VARGHESE S CHOORALIL

Design Engineering