TMM 4112:
Mechanical design of Machine Elements

Basic functions of machines and machine elements as well as the Mechanical integrity of these components are discussed in this bachelor course.

The course contains:

  1. Fatigue design including Wöhler curve and Smith diagrams, the fatigue limit, reduction factors, stress concentrations, multi-axial stresses and spectrum fatigue lifetime based on Rainflow Counting.
  2. Machine and rotor dynamics, respectively spring supported machines, critical speed/rpm, static and dynamic balancing.
  3. Mechanisms and transmissions: Mechanics of the screw, gears.
  4. Couplings and brakes: Disc break (evenly distributed pressure and wear), drum brake (internal and external), fixed and releaseable couplings
  5. Bearings: roller bearings, bearing design, life time assessment.
  6. Springs: torsion, coil, leaf, ring and rubber springs.
  7. Press and shrink-fit connections: deformation of thick-walled tubes, tolerances and fits.
  8. Bolts: threads, load carrying capacity, pretension, tightening/torque moment, bolt diagram.
  9. Welded joints: static and fatigue analyses.

The students learn about machine elements and their design, functional principles, mechanisms, and integration in machinery. They get to know the functions of some common machine elements and the solution of design and engineering problems associated with these. Further, they will establish structural and dynamics models for mechanical behavior with basis in subsystem or component, apply design criteria for different (mechanical) functional and requirements and choose reasonable design and engineering solutions.


  1. G. Härkegård: Dimensjonering av maskindeler, Tapir Akademisk Forlag, Trondheim, 2004.
  2. J.A. Collins, H.R. Rusby, G.H. Staab: Mechanical Design of Machine Elements and Machines: A Failure Prevention Perspective, Wiley 2010
Further details at NTNU