Research
3D Dynamic Fracture in Heterogeneous Media

3D Dynamic Fracture in Heterogeneous Media

Led by:  Principal Investigator: Dr.-Ing. Stefan Löhnert - French Co-Advisor in Cachan: Prof. Pierre-Alain Guidault
Team:  Mahmoud Pezeshki
Year:  2014
Funding:  DFG (Graduiertenkolleg 1627)
Remarks:  DFG (Graduiertenkolleg 1627)

Project Description

    In this project crack growth in brittle media is being investigated by means of the eXtended Finite Element Method (XFEM) and damage mechanics. XFEM is a numerical method, based on the Finite Element Method (FEM), which is especially designed for treating non-smooth problems such as cracks. An essential advantage of the XFEM is that the finite element mesh does not require updating to be able to track the crack path. Enrichments added to classical FE models take into account the effects of a crack or discontinuity.
    In fiber reinforced materials a fracture process often starts with the delamination between the matrix material and the fibers. At some point these crack propagation processes may lead to an abrupt rupture of the entire structure.


    A gradient enhanced damage model is being utilized to evaluate degradation of the material at each point of the domain. In gradient enhanced damage models, a chosen length scale behaves as a localization limiter and describes the influence of the microstructure on the damage process. Moreover, such a model smoothes the deformation of the structure and avoids energy dissipation in a narrow band (surface). Damage values obtained based on this approach are used as the crack propagation criterion.

   

More about the Principal investigators and researcher

 Principal Investigators:     

                                 

  • Dr.-Ing. Stefan Löhnert
    Leibniz Universität Hannover  Email
  • Prof. Dr.-Ing. habil. Peter Wriggers
    Head of The Institute of Continuum Mechanics  Email
  • Dr. Pierre-Alain Guidault
    Co-Advisors in Universite Paris-Saclay, LMT Cachan Email    
  • Dr. Emmanuel Baranger 
    Co-Advisors in Universite Paris-Saclay, LMT Cachan Email

Researcher:  

  • Mahmoud Pezeshki 
    Leibniz Universität Hannover