Undergraduate Engineering Mechanics at the ETH

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Undergraduate Engineering Mechanics at the ETH

• Stephan KaufmannInstitute of Mechanical
  SystemsETH Zürich

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Outline

• http//www.ifm.ethz.ch/kaufmann/owf/
• Curriculum
• The computer as a teaching aid
• MECA
• Simulations
• Java applets
• Mathematica packages

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Engineering Mechanics Courses

• 3-semester course (Dual/Sayir)
• Mechanical and Process Eng. (200 stud. 3 sem.)
• Civil Eng. (60 stud. 2.5 sem.)
• Materials Sciences (60 stud. 2 sem., 3rd
  optional)
• 1-semester course (Brauchli)
• Electrical Eng. (160 stud. 1st sem.)
• 1-semester course (Kaufmann)
• Environmental and Geomatics Eng.(60 stud. 2nd
  sem.)

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Organization (Mech. Proc. Eng.)
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1st Semester (Statics)

• Kinematics of rigid bodies (velocities)
• Forces, moments, systems of forces, resultant,
  moment resultant, equivalence, reduction, center
  of gravity, power
• Principle of Virtual Power, equilibrium
• Supports, systems, trusses
• Friction, cables
• Shear force, bending- and torsional moment

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2nd Semester (Strength of Materials)

• Stress tensor, Mohrs circle
• Strain tensor
• Linear elasticity
• Deflections of beams
• Torsion
• Deformation energy, Castiglianos theorem
• Buckling of beams
• Plasticity

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3rd Semester (Dynamics)

• Acceleration
• Equations of motion (dAlembert, PVP)
• Vibrations (1 and N degrees of freedom)
• Vibrations of beams longitudinal, bending
• Waves in beams longitudinal, bending
• Relative motion
• Kinetics of rigid bodies in 3-d, gyroscopes
• Lagranges equations
• Impact or (gravitation introd. to spec. rel.)

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MECA Ideas

• Fill in the gap between lectures and exercises
  (passive/active learning)
• Place a "24h-teacher" at the students disposal
• Lead the students through "good" solutions of
  home exercises
• Force the students to think about aspects which
  usually are forgotten (modeling etc.)
• Show and prevent the well-known pitfalls
• The system is optional and anonymous
• The system must be user-friendly!

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MECA Demonstration
Click icon to start MECA
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MECA History

• Pilot project 85-88
• Prototypes pilot group
• Authoring system by SK
• Teachware by professors and assistants
• Serious didactical evaluation was impossible
• Unexpected positive social effect
• Dedicated MECA-room with 20 Macs 1988-98
• Java-version in 1998 (3 months)

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MECA Conclusions

• The students feedback is very polarized from
  "very good" to "useless"
• The system seems to be attractive mainly for less
  talented students
• These students tend to spend a lot of time on the
  system, working with a questionable didactical
  efficiency
• A great majority of the students want the system
  to be available
• Teachware is very expensive

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Simulations Ideas

• Computer simulations of dynamical effects in
  lectures
• Complement real experiments
• Allow the students to run simulations and explore
  effects on their own computers

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Simulations History

• 1985-1986 Development of some programs on a PC
  (R. Triebe)
• 1986-1989 New programs for the Mac using
  DialogMachine (several students and SK)
• since 1999 new implementations using Java (M.
  Bergdorf and SK)

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Simulations Examples

• Pole curve
• Cycloids
• Planet gear
• Pendulum
• Double pendulum
• Oscillator

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Mathematica Package

• The package is available at http//www.ifm.ethz.c
  h/kaufmann/
• This notebook contains a sample Beam