Design Area Examination
Goal: The purpose of the Design Area exam is to establish a PhD student’s proficiency in the principles of design and analysis of machines and machine components with emphasis on design for motion, forces, strength and reliability.
Scope: As a reference, specific subjects that may be included in the exam are listed below:
- Kinematic analysis (position, velocity, acceleration, and point path) of one degree of freedom planar mechanisms with both lower pairs and higher pairs
- Static failure and factor of safety for both ductile and brittle materials
- Energy method and Castigliano’s method
Fatigue failure and factor of safety
- Stress - cycle (SN) diagram, endurance limit and Marin factors
- Stress concentration and notch sensitivities
- Fully reversed stress and non-zero mean stress
- Goodman Diagram
- Combined loading
- Surface fatigue
Design and selection of common machine components:
- Bolts and bolted joints: bolt geometry/strength/stiffness, membrane stiffness, preload, joint constant, static/fatigue factor of safety
- Helical/torsion springs: geometry and loads, spring rate and stresses, static/fatigue failure
- Spur gears: geometry and loading, stresses and strength, bending and contact factor of safety
- Shafts and keyways
- Roller element bearings: radial loading, combined loads, bearing selection
- Journal bearings: Petroff’s Law, Reynolds Equation
- Brakes and clutches: short/long shoe brakes, uniform pressure and wear, disk clutch and brakes
Exam format and passing criteria: The design area exam is a supervised, two-hour, open-book (limited to 4 books) written examination. Calculators (per ME calculator policy) and technical drawing tools (rulers, set squares, protractor, and compass) may be used during the examination. Students must meet the pass criterion set by the design area faculty members.
Recommended Textbooks to Bring to the Exam
Richard Budynas and Keith Nisbett, Shigley's Mechanical Engineering Design, 11th Edition, McGraw Hill, 2020.
John J. Uicker, Jr., Gordon R. Pennock, and Joseph E. Shigley, Theory of Machines and Mechanisms, 5th edition, Oxford University Press, 2016.