Session: 13-11-02: Friction, Fracture, and Damage II

Paper Number: 165281

Ansys-Smart Crack Growth Technology Meets the Phase-Field Approach 

Simulating crack growth is crucial for designing products that prevent early failures. Engineers often focus on modeling stationary cracks in complex shapes and understanding the fracture mechanics of these cracks, as simulating crack growth can be highly complex. Some commercial software can simulate crack growth after performing finite element analysis (FEA), but these tools are typically limited and challenging to use. Alternative methods, such as mesh-free methods, Phase-Field, and extended finite element method (XFEM), offer solutions, each with its own set of advantages and disadvantages depending on the complexity of the simulation. To address these challenges, Ansys recently introduced a new feature called SMART (Separating, Morphing, Adaptive, and Remeshing Technology). This feature provides an easy-to-use, automated way to simulate crack growth in 3D models for both fatigue and static cracks. 

SMART crack growth method is a powerful tool that uses fracture parameters, such as the stress intensity factor and J-integral, as a criterion to model discrete macrocracking and simulate crack propagation under complex static and fatigue loading conditions. While it is widely used in the industry due to its robustness and simulation cost efficiency, it may face challenges when dealing with complex crack patterns, such as crack branching or merging. Additionally, under complex non-proportional loadings, SMART crack growth method uses linear elastic approaches to define local stress intensity factor, which inadequately captures the behavior of microcracks. Although Phase-Field method is widely accepted within the fracture community and may address some of the challenges that discrete fracturing cannot solve, it comes with a significant increase in computational cost due to element size and may lead to failure to converge simulations, especially for unstable crack growth. 

The combination of the SMART crack growth method and the Phase-Field Approach offers a more accurate description of the transition between continuum and discrete fracturing, especially under complex loading conditions. It also enables the use of coarser meshes compared to traditional Phase-Field methods, while still providing accurate results and better solution convergence for unstable cracks. Unlike SMART crack growth, this approach eliminates the need for explicit crack extension surface representations and post-processing for fracture parameter calculation. Crack growth is instead described by the Phase-Field pattern, while the energy release due to the creating new crack surface defined by the Phase-Field simulation. Thus, it simplifies the simulation of various fracture problems, including crack initiation, propagation, and complete separation, while enabling to solve more complex scenarios, such as crack merging and branching. Additionally, this method addresses the challenges faced by the Phase-Field approach under compression and during crack surface penetration under complex loading. 

In this study, a brief review will be given on the advantages of the combination of SMART and the Phase-Field method, and the computational challenges involved in simulating general fracture processes will be discussed. 

Presenting Author: Kaan Ozenc Ansys Inc.

Presenting Author Biography: Dr.-Ing Kaan Ozenc (PhD) is a highly accomplished and dedicated engineer with a passion for advancing the field of fracture mechanics and computational modeling. With a background in civil engineering and extensive experience in both industry and academia, Ozenc has made significant contributions to the understanding of the general fracture behavior in not only for linear elastic materials but also in elastomers and viscoelastic solids.
As a Research and Development Engineer at ANSYS Inc. , Ozenc has played a pivotal role in the development and verification of cutting-edge technologies, including the SMART crack growth method. He has also made valuable contributions to fracture mechanics tools like interaction integrals and J-integrals, further enhancing the capabilities of ANSYS software.
Before joining ANSYS, Ozenc served as a Scientific Staff member at the Institute of Structural Analysis at TU Dresden, Germany. During this period, he actively participated in ongoing research endeavors and was instrumental in implementing the material force approach into ANSYS, benefiting the company with enhanced material modeling capabilities.

Ozenc's academic journey includes research towards a PhD at TU Dresden, where his thesis, titled "Approaches to model failure of materials by configurational mechanics," reflects his deep understanding of the subject matter. Additionally, he earned a Master of Science degree from the Middle East Technical University (METU) in Ankara, Turkey, focusing on finite element simulation of crack propagation for steel fiber reinforced concrete.

Beyond his professional achievements, Ozenc is proficient in multiple programming languages, including Fortran, C++, and Python.

Ozenc is a forward-thinking engineer who continues to push the boundaries of fracture mechanics and computational modeling. His dedication to innovation and problem-solving makes him a valuable asset in any engineering endeavor.

Authors:

Kaan Ozenc Ansys Inc.
Guoyu Lin Ansys Inc.
Bo Lin Ansys Inc.