MTU Aero Engines develops, manufactures, sells and services commercial and military propulsion systems for airplanes and helicopters, as well as industrial gas turbines. The key to our success is developing the propulsion systems of tomorrow —even more economical, lower in emissions and quieter. With roughly 10,000 employees, we are present around the world, but we make our home in Germany. You, too, can become part of our dedicated Team:

Writer (f/m/d) of a master thesis : Development of a Simplified Slip-Plane based Material Model for Plasticity Calculations in Single Crystals

Single crystals are orthotropic materials characterized by three independent elastic constants. They are manufactured by carefully controlling the temperature during cooling of the liquid metal. The anisotropy in the elastic range is easily taken into account. In the plastic range, though, the motion along the crystallographic slip planes has to be modeled, leading to complicated material models. One such model has been developed by G. Cailletaud and was implemented in the free Finite Element Program CalculiX. A detailed description can be found in G. Dhondt, The Finite Element Method for Three-Dimensional Thermomechanical Applications, Wiley 2004, Section 5.4.

The aim of this thesis is to develop a simple slip-plane based plasticity model for single crystals for everyday use. Starting point for this development is the Cailletaud model. The model to be developed should be characterized by as few parameters as possible, while still accurately describing the plastic behavior. Since material testing is expensive, testing requirements should be kept to a minimum. A corresponding testing matrix should be proposed in order to determine the unknown constants in the model. The model has to be implemented in CalculiX (www.calculix.de) and should be applied to simple testing specimens first. Finally, real engine components should be calculated with the model in order to demonstrate its effectiveness and stability of the numerical implementation.

 

Tasks:

  • to get acquainted with the Cailletaud model and its implementation in CalculiX
  • to modify and/or simplify the model if necessary
  • to determine the material parameters using available test data
  • to propose a minimum test matrix in order to be able to determine the material constants for future material developments and to devise a scheme how to obtain the material constants from the raw test data
  • to apply the model to simple test examples and, later on, to real engine components

Requirements:

  • engineering or physics major
  • substantial interest in nonlinear material modeling
  • good knowledge of the finite element method and numerical algorithms
  • willing to program in C and FORTRAN
  • good knowledge of the English language
  • citizen of the European
  • Duration: 6 months

Are you interested in the job? Give your career a boost and send us your complete application (Letter of Motivation, CV, Transcript of Records, High School Diploma).

We look forward to getting to know you.