tailieunhanh - Fundamentals of Machine Design P1

Design is essentially a decision-making process. If we have a problem, we need to design a solution. In other words, to design is to formulate a plan to satisfy a particular need and to create something with a physical reality. Consider for an example, design of a chair. A number of factors need be considered first: (a) The purpose for which the chair is to be designed such as whether it is to be used as an easy chair, an office chair or to accompany a dining table. | Module 1 Fundamentals of machine design Version 2 ME IIT Kharagpur Lesson 1 Design philosophy Version 2 ME IIT Kharagpur Instructional Objectives At the end of this lesson the students should have the knowledge of Basic concept of design in general. Concept of machine design and their types. Factors to be considered in machine design. Introduction Design is essentially a decision-making process. If we have a problem we need to design a solution. In other words to design is to formulate a plan to satisfy a particular need and to create something with a physical reality. Consider for an example design of a chair. A number of factors need be considered first a The purpose for which the chair is to be designed such as whether it is to be used as an easy chair an office chair or to accompany a dining table. b Whether the chair is to be designed for a grown up person or a child. c Material for the chair its strength and cost need to be determined. d Finally the aesthetics of the designed chair. Almost everyone is involved in design in one way or the other in our daily lives because problems are posed and they need to be solved. Basic concept of machine design Decision making comes in every stage of design. Consider two cars of different makes. They may both be reasonable cars and serve the same purpose but the designs are different. The designers consider different factors and come to certain conclusions leading to an optimum design. Market survey gives an indication of what people want. Existing norms play an important role. Once a critical decision is made the rest of the design features follow. For example Version 2 ME IIT .