Forschung
Meshfree Methods

Improving Accuracy and Performance of Meshfree Methods

Simulation driven engineering is nowadays an essential part in the development process. Especially in the field of subtractive or additive manufacturing their is an increasing interest on high fidelity modeling. Due to their flexibility meshfree solution schemes are very attractive for the simulation of such processes which involve intrinsic and varying discontinuities.

Many meshfree methods were developed over the years. However all of these schemes to model continua need either special stabilization algorithm, regularization techniques or correction schemes to reproduce the behavior of academic test examples. However, even an approximate prediction of real dynamic systems can not be guaranteed with these methods. Additionally, unphysical parameters have to be determined, if such stabilization, regularization or correction schemes are used.

Nevertheless, in order to be able to make reliable statements in the high fidelity modeling of engineering applications the need on more flexible solution schemes which ensures robustness, efficiency and accuracy is still present.

The shortcomings of truly meshfree methods result mostly from a violation of mathematical requirements on computational solution schemes, like the consistency conditions or the integration constraint. Additionally, phenomena like under-integration can likely occur.

A meshfree solution scheme which exhibits the same accuracy as the meshbased Finite Element Method, which can be applied for all engineering application cases and which is robust and efficient is still not found.

Improving Accuracy and Performance of Meshfree Methods

  • Numerical simulation of pile installation in a hypoplastic framework using an SPH based Method
    In this project, a 3D computational tool using smoothed particle hydrodynamics (SPH) is developed which based on a hypoplastic constitutive approach for the mechanical behavior of the soil. The numerical code is firstly validated against a benchmark problem. Then several test cases are simulated including monotonic and vibratory penetration of piles into the soil. A good agreement with the experimental observation is found. Additionally, the impact of pile running in the presence of sheetpiles (retainers) are investigated to see how pile running can alter the applied forces on the sheet piles. The simulation of such complex geotechnical problems which involve large deformation, material nonlinearity and moving boundary conditions demonstrates the applicability and versatility of the proposed numerical tool in this field.
    Leitung: Peter Wriggers
    Team: Meisam Soleimani, Christian Weißenfels
    Jahr: 2020
  • Peridynamic Petrov-Galerkin Method
    The flexibility of meshless methods in dealing with varying discontinuities and phases makes them attractive for the simulation of various engineering applications. Peridynamics is a integro-differential formulation of the momentum equation, which is widely used for modeling fractures based on non-local material models. The usage of local material models from classical continuum mechanics theory is enforced by a correspondence formulation. This approach is accompanied by the drawback of low-energy modes which result in spurious oscillations. In this project, the Peridynamic Petrov-Galerkin (PPG) method is developed, that provides a generalized correspondence formulation which is free of low-energy modes without the use of unphysical corrections.
    Leitung: Christian Weißenfels, Peter Wriggers
    Team: M.Sc. Tobias Bode
    Jahr: 2019
  • Using Machine Learning to Improve the Modelling of Machining and Cutting Processes
    Metal cutting is a fundamental process in industrial production. The fast and accurate on-line prediction of metal cutting processes is crucial for the Intelligent Manufacturing (IM). With the advent of high-speed computing, robust numerical algorithms and machine learning technology, computational modelling serves as a tool for not only accurate but also fast predicting the complex machining processes and understanding the complex physics. In this work, the machine learning based numerical model is developed for simulation of metal cutting processes.
    Leitung: C. Weißenfels, P. Wriggers
    Team: M.Sc. Dengpeng Huang
    Jahr: 2018
    Förderung: China Scholarship Council (CSC)
  • ISPH-based Simulation of the Selective Laser Melting Process
    Development of a thermo-mechanical model for the simulation of the SLM process.
    Leitung: Christian Weißenfels, Peter Wriggers
    Team: M.Sc. Jan-Philipp Fürstenau
    Jahr: 2017
  • Process Simulation for Selective Laser Melting
    A phase change model for solution with the meshfree Galerkin OTM method is developed.
    Leitung: Christian Weißenfels, Peter Wriggers
    Team: M.Sc. Henning Wessels
    Jahr: 2016
  • 3D-Printing of Curing Polymers
    3D-Printing simulations of curing polymers within the concept of Peridynamics are developed.
    Leitung: Christian Weißenfels, Peter Wriggers
    Team: M.Sc. Philipp Hartmann
    Jahr: 2016
    Förderung: DFG (Graduiertenkolleg 1627)

PROJECT COORDINATORS

Prof. Dr.-Ing. habil. Dr. h.c. mult. Dr.-Ing. E.h. Peter Wriggers
Geschäftsführende Leitung
Adresse
An der Universität 1
30823 Garbsen
Gebäude
Raum
317
Prof. Dr.-Ing. habil. Dr. h.c. mult. Dr.-Ing. E.h. Peter Wriggers
Geschäftsführende Leitung
Adresse
An der Universität 1
30823 Garbsen
Gebäude
Raum
317