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 (m/f/d) of a diploma or master thesis: Testing a Slip-Plane based Material Model for Creep Calculations

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 viscoplastic range, though, the motion along the crystallographic slip planes has to be modeled, leading to complicated material models. The simplest of these models has been developed by G. Cailletaud and was implemented in the free Finite Element Program CalculiX.

If pure creep is considered (no plasticity) this model can be further simplified. The only material constants to be determined are the creep model constants within each slip plane. In a previous master thesis algorithms were developed to calculate stresses and strains due to creep using this Cailletaud-type model. Input data to the model are creep test results on <001> and <111> specimens and described by Larson-Miller parameters. This model has been applied to a couple of realistic engine components. Before the model can be released for general use, however, further intensive testing is necessary. This relates to the accuracy, the stability as well as the computational speed of the model.

Tasks

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 viscoplastic range, though, the motion along the crystallographic slip planes has to be modeled, leading to complicated material models. The simplest of these models has been developed by G. Cailletaud and was implemented in the free Finite Element Program CalculiX.

If pure creep is considered (no plasticity) this model can be further simplified. The only material constants to be determined are the creep model constants within each slip plane. In a previous master thesis algorithms were developed to calculate stresses and strains due to creep using this Cailletaud-type model. Input data to the model are creep test results on <001> and <111> specimens and described by Larson-Miller parameters. This model has been applied to a couple of realistic engine components. Before the model can be released for general use, however, further intensive testing is necessary. This relates to the accuracy, the stability as well as the computational speed of the model.

The Thesis work includes:

  • to get acquainted with the Cailletaud model and its implementation in CalculiX
  • to apply the model to a variety of realistic engine components
  • To monitor the stability, accuracy and computational speed
  • in case of deficiencies, analyze the (FORTRAN) code, identify the source of the problems and come up with solution methods.

Requirements

  • master studies in the field of engineering or physics
  • substantial interest in nonlinear material modeling
  • good knowledge of the finite element method and numerical algorithms
  • willingness to program in C and FORTRAN
  • good knowledge of the English language

Duration: 6 months

We offer

  • Insights into practical work in aviation as an innovative, high-tech industry
  • Exciting jobs that carry responsibility and are performed in an atmosphere of team spirit
  • A personally assigned contact and individual support services
  • Flexible working hours and compensatory time off
  • Networking opportunities

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.