AAE 45400 Design of Aerospace Structures


Design/failure criteria for aerospace structures, materials selection, introduction to manufacturing methods, structural assemblies, component details, concurrent engineering, and interdisciplinary design teams.

Format: 3 hours of lecture per week

Credit hours: 3

Status: Elective, Structures

Offered: Fall

Pre-requisite: AAE 352 or consent of instructor

Co-requisite: None

Course Instructor: Professor Grandt

Text: Printed class notes consisting of reports and other design related materials

Assessment Method: Take-home examination (20 %), Term paper (oral 10%, written 10%), Design/build/test project (25 %), homework (35 %)

Course Objectives:

  1. Technical Subjects: Provide background and experience in technical issues associated with structural design: failure criteria (fatigue, fracture, buckling, corrosion, etc.), design constraints, loads, materials selection, manufacturing issues, joints & assembly methods, stress analysis, nondestructive inspection
  2. Enabling Topics: Provide opportunities to develop other skills needed for the successful designer: technical communications (oral and written), technology assessment & transition, teamwork issues, economic considerations, creativity & problem solving techniques, engineering ethics, case histories, regulatory & certification topics, total quality management, personal development skills
  3. Design Projects: Both individual and team projects are used to provide experience in the various aspects of component design, with particular emphasis given to "what if" type trade studies. One major assignment involves teaming with another class in the Department of Aviation Technology on a project that involves designing, building, and testing a minimum weight and cost component subjected to several other specified design constraints. Both oral and written reports are prepared for this project

Necessary Background:

  1. Vector calculus and differential equations through PDE's
  2. Ability to write a computer program to solve a system of equations
  3. Analysis of aircraft structures
  4. Mechanical behavior of materials

Topics (number of Lectures):

  1. Introduction (3 classes) nature of design process; review stress-strain behavior and stress/displacement formulae
  2. Design Constraints (3 classes) loads; overview failure criteria (elastic deformations, yield, creep, corrosion, fatigue, fracture); other design constraints (weight, costs, performance, etc.)
  3. Mechanical Joints (4 classes) overview welds, bonded joints and fasteners; attachment lugs; load transfer/stress analysis issues
  4. Manufacturing Issues (2 classes) dimensioning, tolerances, overview of manufacturing methods
  5. Damage Tolerant Design (6 classes) introduction to linear elastic fracture mechanics (fracture toughness, fatigue crack growth), damage tolerant design criteria, leak before break
  6. Corrosion prevention (2 classes)
  7. Fatigue (3 classes) overview stress and strain life concepts for prediction fatigue crack formation, lab demonstration, fatigue improvement processes (shot peening, cold-working, and repair)
  8. Overview Aerospace Materials (4 classes) Mil Handbook 5 data, aerospace material usage, material characteristics and properties (aluminum, steel, titanium, composites, advanced materials), performance indices, trade-studies
  9. Buckling (2 classes) columns, plates, local crippling
  10. Non-destructive inspection (2 classes) inspection goals and reliability, overview inspection methods
  11. Case histories of component failures and design deficiencies (2 classes)
  12. Enabling topics (4 classes) teamwork issues, assessment of technology maturity, creative problem solving, preparation of written and oral reports, ethical issues
  13. Design reviews and component testing (3 classes)
  14. Term paper presentations (5 classes)

Relationship of course to program objectives:

This elective course is intended to provide additional background in technical and enabling topics related to structural design. The technical aspects of the School's program objectives (1) are developed through discussion of failure criteria, materials selection, manufacturing issues, assembly methods, etc. Topics intended to develop basic engineering skills (Objective 2) include several open-ended homework and design problems (Objective 2a), and short class discussions of ethical issues taken from the Lockheed-Martin "Ethics Challenge" program (Objective 2d). One major design-build-test project involves matching students from this class with students from a class in another department (Aviation Technology AT 406). This open ended (Objective 2a) effort provides experience in working with interdisciplinary teams (Objective 2b), written and oral communications (Objective 2c), and manufacturing and testing a component designed to satisfy specified criteria. Students also prepare a written and oral term paper on some aspect of research dealing with new structural technology (Objectives 2c, 3, 4)

Prepared by: Prof. A. F. Grandt, Jr.

Date: February 14, 2001