MT-1620 al.2002 Unit 1 Introduction and Design Overview Paul A Lagace, Ph. D Professor of aeronautics Astronautics and Engineering Systems Paul A Lagace @2001
MIT - 16.20 Fall, 2002 Unit 1 Introduction and Design Overview Paul A. Lagace, Ph.D. Professor of Aeronautics & Astronautics and Engineering Systems Paul A. Lagace © 2001
MT-1620 al.2002 Need to study structural mechanics to design properly to prevent failure There is no doubt that any of the disciplines of Aeronautics and Astronautics can contribute to an accident -engine failure etc But, the vast majority of non-human induced accidents is due to structural material) failure(ultimately Purpose of 16.20: Provide you with the tools to properly Design"Aerospace Structures"to assure"structural integrity (i.e, it doesnt fail) Note, 16.20 mainly oriented in past to aircraft structures because that is where the main experience lies. We will try to generalize and show examples for space structures Paul A Lagace @2001 Unit 1 -p 2
MIT - 16.20 Fall, 2002 Need to study structural mechanics to design properly to prevent failure There is no doubt that any of the disciplines of Aeronautics and Astronautics can contribute to an accident -engine failure -etc. But, the vast majority of non-human induced accidents is due to structural (material) failure (ultimately). Purpose of 16.20: Provide you with the tools to properly Design “Aerospace Structures” to assure “structural integrity” (i.e., it doesn’t fail) Note, 16.20 mainly oriented in past to aircraft structures because that is where the main experience lies. We will try to generalize and show examples for space structures. Paul A. Lagace © 2001 Unit 1 - p. 2
MT-1620 al.2002 Aeronautics and Astronautics deal with three major categories of structures 1. Aircraft(atmospheric vehicles 2 Launch vehicles 3. Space structures (partially a civil engineering task? Note: Transatmospheric vehicles can be combinations of 1 and 2 .. the shuttle is IMPORTANT: Many of the design considerations for these three categories are different, but the same techniques and concepts are used to analyze the structures(basically) In fact, except for special design considerations, the techniques used for all structures are basically the same Paul A Lagace @2001 Unit 1 -p 3
MIT - 16.20 Fall, 2002 Aeronautics and Astronautics deal with three major categories of structures: 1. Aircraft (atmospheric vehicles) 2. Launch vehicles 3. Space structures (partially a civil engineering task?) (Note: Transatmospheric vehicles can be combinations of 1 and 2…the Shuttle is!) IMPORTANT: Many of the design considerations for these three categories are different, but the same techniques and concepts are used to analyze the structures (basically) In fact, except for special design considerations, the techniques used for all structures are basically the same: Paul A. Lagace © 2001 Unit 1 - p. 3
MT-1620 al.2002 Structure type Possible considerations Buildings Ships Cars Space stations Airplanes The difference is often in the degree of refinement of the structural analysis ( generally more refined in A& A! We will teach basic techniques and concepts and use specific examples. But, the technique may apply to another structural type as well EXample:(aircraft to space station) Fuselage -> space station living habitat(pressurized cylinders Paul A Lagace @2001 Unit 1-p. 4
MIT - 16.20 Fall, 2002 Structure type Possible considerations Buildings Ships Cars Space stations Airplanes • • • The difference is often in the degree of refinement of the structural analysis (generally more refined in A & A!) ÆWe will teach basic techniques and concepts and use specific examples. But, the technique may apply to another structural type as well. Example: (aircraft to space station) Fuselage --> space station living habitat (pressurized cylinders) Paul A. Lagace © 2001 Unit 1 - p. 4
MT-1620 al.2002 Overview of Structural design Process (Review from U.E. Purpose: Assure"structural integrity"while minimizing cost In aerospace structures, cost often means weight Why? Saving a pound of weight means more payload(extra passengers, more satellites fuel(longer distance, longer duration via extended station keeping Amount industries(civilian)are willing to pay to save a pound of weight Satellites 10,000-$20,000( N/o servicing) Transport aircraft 100-$200 General aircraft 25 Automobile ~9000 Paul A Lagace @2001 Unit 1 -p 5
MIT - 16.20 Fall, 2002 Overview of Structural Design Process (Review from U.E.) Purpose: Assure “structural integrity” while minimizing cost In aerospace structures, cost often means weight. Why? Saving a pound of weight means more - payload (extra passengers, more satellites) - fuel (longer distance, longer duration via extended station keeping) • • • Amount industries (civilian) are willing to pay to save a pound of weight: Satellites $10,000 - $20,000 (w/o servicing) Transport Aircraft $100 - $200 General Aircraft $25 Automobile ∼ $0.00 Paul A. Lagace © 2001 Unit 1 - p. 5