30.207 Structural Mechanics and Design

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This course presents a solid foundation of the fundamentals of structural mechanics, from the macro-level of structural analysis to the molecular level of materials science and engineering. Students will learn and appreciate how structural analysis and materials response are intricately involved in the engineering product/device design process. Fundamental concepts of  materials failures (including fracture, fatigue and creep) and their microstructural origins (in important engineering materials including metals, ceramics, polymers and composite – be it structural or elemental) will be introduced in the class, with emphasis on structural design for safety and reliability. In these aspects, the class could be likened to the popular CSI (Crime Scene Investigation) TV series where in every episode, the students will be presented with the “dead bodies in the crime scene” (ie. the failed components of an engineering systems/devices) and based on the “forensic knowledge”, they will be asked to “solve the case” (ie. based on structural mechanics knowledge, the students of this class will solve how the engineering systems/devices fail and how that led to the final catastrophic events that result in the failed parts found in the accident scene). Relevant principles and concepts in several applications – from design of large mechanical structures in civil engineering, to transportation (aerospace, automotive, etc.), to marine as well as high technology often in micro/nano-scale  (microelectronics, energy, solar PV, battery, etc.) industries – will be discussed. Throughout the course, emphasis will be placed on the foundations of structural mechanics, relevant design applications in the various fields of industries in Singapore, problem-solving, experimental design, and data analysis.

Pre-Requisite

Course Lead/Main Instructor

Goal

This is a continuation from the topics in 30.001 as well as 30.108. It extends beyond the basic structural analysis of most common structural members taught in 30.001 (Structures and Materials) as well as potentially in 30.105 (Machine Elements Design), and explores the more foundational elements of the analysis. It deepens the knowledge of the mechanics for the most common structures and materials used in the real world applications.

Learning Objectives

By the end of the course, students will be able to:

  • Describe the elastic behavior of common mechanical structures used in engineering applications (beams, columns, cables and shafts);
  • Explain various theoretical methods to analyze elastic and plastic buckling of columns, thin-walled sections and plates;
  • Perform structural analysis of product/device design and use it for design for safety/reliability
  • Perform a failure analysis of mechanical structures – from the structural analysis to the materials point of views;
  • Describe the mechanical responses of the most important classes of engineering materials;
  • Examine the knowledge base of various design cases from aerospace, automotive, microelectronics and renewable energy fields (solar PV, battery, etc.)

Measurable Outcomes

After completing the course, students will be able to:

  • Identify the basic principles of structural mechanics, analyze mechanical structures and how these concepts relate to design of engineering product/device
  • Describe the various methodologies for structural design for safety and reliability and understand the foundation of the methodologies from first principles
  • Construct full structural analysis of beam, shaft, thin wall/film, column, cable, etc.
  • Analyze failures of structures and their materials/microstructural origins

Pedagogy

Every week, students will attend cohort classes twice (2.5 h each). Each cohort will provide an overview of the main concepts that the students will require and these concepts will be reinforced through problem solving and active-learning activities.  In each week, the first cohort class will be dedicated to lecture (with interactive learning activities) while the second cohort class will be dedicated to either a real-world case study, a practical lab session or a design project studio (especially in the second half of the term/after mid-term exam). There will be homework for every week. Attendance is expected in all cohort classes and will be checked through the use of clickers. Weekly work will consist of pre-class reading, online video lectures, after class online multiple choice questions (MCQs), and graded problem sets.  There will be mid-term exam and final exam. Finally, students will work for the 1D design project in groups starting on the third week of the term and ending in the final week of the term. Students are expected to fully participate in any project.

1D Design Project:

  • 1D Design Challenge: To design solar cells interconnection technology (materials,
  • shapes/geometry, processes, etc.) to enable fracture-free, thin silicon solar PV systems (that will lead to next generation, lower cost and higher performance solar PV systems in the world)
  • Design project is open-ended and not only involves in-depth structural mechanics analyses but also creativity and innovations
  • Students (of groups of students) will come up with different designs to achieve the same objective/challenge
  • They will learn first the basic failure modes, the origin and evolution of deformation mechanisms, engineering the materials responses, and all basic PV technologies to equip them with sufficient knowledge to come up with a solution/design that achieves the objective
  •  They will the have the chance to design and use computational tools to help them optimize their design, and then later build prototype and validate their design using all the tools/expertise available in the XPV (Xtreme PV Lab) in SUTD (Building 1, basement)

Lectures with interactive learning activities:

  • web-based interactive learning system/activities (eg. Materials mechanical testing, crystallography and failure modes, etc.)
  • hands-on activities or demonstration using daily materials (eg. Ductile vs. brittle failure modes of materials, failure modes due to mechanical testing, etc.)

Case studies with failed components from real-world engineering systems/devices:

  • case studies will be developed taking examples from aerospace engineering, biomedical device engineering and microelectronics
  • some other case studies could be developed from cutting-edge research studies/investigations (in areas of solar PV, battery/energy storage and extreme environments) as more in-depth structural mechanics analysis and involving more hands-on activities or demonstration using more advanced concepts

Laboratory sessions for advanced mechanical characterization/testing skills (nanomechanical testing, AFM, micro/nanofracture testing, etc.)

  • advanced fracture testing (which could include the time-dependence as well as temperature-dependence) on real engineering materials (metals, polymers, ceramics, composites)
  • microbeam bending experiment (and watching the experiment while it is happening inside an SEM)
  • micropillar compression experiment (plasticity at the small scales)
  • peeling test of a single nanofiber (interface adhesion strength of a nanofiber-based “gecko” materials)
  • alternative sessions which could also involve reverse engineering of existing devices/systems or advanced failure analysis of selected devices/systems

Text & References

Required

  • Title:  Advanced Mechanics of Materials and Applied Elasticity, 5th Ed.
    Authors:  Ansel C. Ugural, Saul K. Fenster
    Publishers: Prentice Hall, 2012 ISBN-13: 9780137079810
  • Title:  Roark’s Formulas for Stress and Strain, 8th Edition
    Authors:  Warren C. Young, Richard G. Budynas, Ali Sadegh
    Publishers: McGraw-Hill, 2012
    ISBN-13: 978-0071742474; ISBN-10: 0071742476
  • Title:  Handbook of Materials Failure Analysis with Case Studies from the Aerospace and Automotive Industries
    Authors:  A.S.H. Makhlouf and M. Aliofkhazraei
    Publishers: Butterworth-Heinemann, 2015
    ISBN: 978-0128009505

Recommended

  • Title:  Engineering Materials – An Introduction to Properties, Applications and Design 4th Edition
    Authors:  Michael F. Ashby, David. R. H. Jones
    Publishers: Elsevier, 2012
    ISBN: 9780080966656
  • Title:  Mechanical Behavior of Materials
    Authors:  Norman Dowling
    Publishers: Pearson, 2012
    ISBN: 978-0273764557
  • Title:  To Engineer is Human: The Role of Failure in Successful Design
    Authors:  Henry Petroski
    Publishers: Vintage Books, 1992
    ISBN: 978-0679734161
  • Title:  Imperfections in Crystalline Solids
    Authors:  Cai and Nix
    Publishers: Cambridge University Press, 2016
    ISBN: 9781107123137
  • Title:  Theory of Elasticity
    Authors:  Timoshenko and Goodier
    Publishers: McGraw-Hill, 1970

Grading

Assessment Items

Points (%)

Period

Homework + Labs

20

Throughout the course

Mid-term Exam

20

Week 6

1D Design Project

30

Week 3 – 13

Final Exam

30

Week 14

Total

100

Policies

Exams

There are one 2-hour mid-term exam (week 6) and one 2-hour final exam (week 14). The exams are closed-book and closed-notes.  Required equations and a materials properties table will be provided. Both mid-term and Final exams are compulsory.  Any other situation will be treated as case-by-case basis. Requests for re-grading of tests and exams would be accepted within one week after the answer scripts are handed out.  During re-grading, the whole answer script will be reviewed, not just the particular question queried by the student. The final grade may improve or worsen after complete review.

Assignments and Activities

There are several types of assignments for this course. They include graded in-class worksheets and graded problem sets.

Worksheets

There will be worksheets for some cohort classroom lessons. Worksheets are designed to help you understand and apply concepts that you have learnt in class.  Students are expected to print out the worksheets for every class.  Where worksheets are to be submitted, students have the responsibility to hand-in their work on time. (Due dates will be provided on the worksheets.)

Graded Problem Sets

There is one set of homework (problem sets) each week. All problem sets are to be submitted on a specified day in the following week by noon. Students hold the responsibility to print a copy of the problem sets, attempt the questions on their own and submit their work on time. Disciplinary penalties will be imposed on any attempt to plagiarize or copy someone else’s work. Please refer to the section on Academic Honesty below for more details. Worked solutions to the problem sets will be posted online, 24 hours after the due date. Late submission within 24 hours after the due date will receive 50% of the grades. A grade of 0% will be given once the solution is posted online (after 24 hours of due date). Homework will be graded and returned. The homework is designed to give you practice in solving problems.  Completion of the weekly homework is essential to understanding and mastering the course material.

Late or Missed Assignments

(covered above)

Attendance

(covered above)

Academic Honesty

All students in this course are expected to complete their own written work on all problem sets and tests.  General discussion of problem set questions is permitted, but sharing of answers is strictly prohibited.  Each student is responsible for producing their own set of answers for all problem sets and exams.  Any student copying answers on a problem set/exam or any student who allows their problem set/exam to be copied will receive a grade of zero for that problem set or test.

2018-07-18T09:35:05+00:00