课程概况
“Machine Design Part I” is the first course in an in-depth three course series of “Machine Design.” The “Machine Design” Coursera series covers fundamental mechanical design topics, such as static and fatigue failure theories, the analysis of shafts, fasteners, and gears, and the design of mechanical systems such as gearboxes. Throughout this series of courses we will examine a number of exciting design case studies, including the material selection of a total hip implant, the design and testing of the wing on the 777 aircraft, and the impact of dynamic loads on the design of an bolted pressure vessel.
In this first course, you will learn robust analysis techniques to predict and validate design performance and life. We will start by reviewing critical material properties in design, such as stress, strength, and the coefficient of thermal expansion. We then transition into static failure theories such as von Mises theory, which can be utilized to prevent failure in static loading applications such as the beams in bridges. Finally, we will learn fatigue failure criteria for designs with dynamic loads, such as the input shaft in the transmission of a car.
课程大纲
Material Properties in Design
In this week, we will first provide an overview on the course's content, targeted audiences, the instructor's professional background, and tips to succeed in this course. Then we will cover critical material properties in design, such as strength, modulus of elasticity, and the coefficient of thermal expansion. A case study examining material selection in a Zimmer orthopedic hip implant will demonstrate the real life design applications of these material properties. At the end of the week you will have the opportunity to check your own knowledge of these fundamental material properties by taking Quiz 1 "Material Properties in Design."
Static Failure Theories - Part I
In week 2, we will review stress, strength, and the factory of safety. Specifically, we will review axial, torsional, bending, and transverse shear stresses. Please note that these modules are intended for review- students should already be familiar with these topics from their previous solid mechanics, mechanics of materials, or deformable bodies course. For each topic this week, be sure to refresh your analysis skills by working through worksheets 2, 3, 4 and 5. There is no quiz for this week.
Static Failure Theories - Part II
In this week we will first cover the ductile to brittle transition temperature and stress concentration factors. Then, we will learn two critical static failure theories; the Distortion Energy Theory and Brittle Coulomb-Mohr Theory. A case study featuring the ultimate load testing of the Boeing 777 will highlight the importance of analysis and validation. Be sure to work through worksheets 6, 7, 8 and 9 to self-check your understanding of the course materials. At the end of this week, you will take Quiz 2 “Static Failure.”
Fatigue Failure - Part I
In week 4, we will introduce critical fatigue principles, starting with fully revisable stresses and the SN Curve. Then, we discuss how to estimate a fully adjusted endurance limit. Finally, a case study covering the root cause analysis of the fatigue failure of the Aloha Airlines flight 293 will emphasize the dangers of fatigue failure. In this week, you should complete worksheets 10, 11 and 12 as well as Quiz 3 “Fully Reversed Loading in Fatigue.”
Fatigue Failure - Part II
In this last week of the course, we will cover the fatigue failure criteria for fluctuating and randomly varying stresses, including key concepts such as the Modified Goodman line and Miner’s Rule. This week be sure to complete worksheets 13 and 14 as well as Quiz 4 “Fluctuating Fatigue and Miner’s Rule.” Finally, take Quiz 5, “The Comprehensive Quiz”, which will measure your overall knowledge of this course.
