The hierarchical finite cell method for problems in structural mechanics

2017 ◽  
Author(s):  
Meysam Joulaian

The finite cell method (FCM) is a combination of the fictitious domain approach and high-order finite elements. This thesis is concerned with the study of the numerical challenges of this method, and it investigates possible approaches to overcome them. Herein, we will introduce and study different numerical integration schemes, such as the adaptive integration method and the moment fitting approach. To improve the convergence behavior of the FCM for problems with heterogeneous material, we will also propose two high-order enrichment strategies based on the hp-d approach and the partition of unity method. Moreover, the application of the FCM will be extended to the simulation of wave propagation problems, employing spectral elements and a novel mass lumping technique. ...

Author(s):  
Ernst Rank ◽  
Alexander Düster ◽  
Dominik Schillinger ◽  
Zhengxiong Yang

2013 ◽  
Vol 10 (03) ◽  
pp. 1350002 ◽  
Author(s):  
ALIREZA ABEDIAN ◽  
JAMSHID PARVIZIAN ◽  
ALEXANDER DÜSTER ◽  
HASSAN KHADEMYZADEH ◽  
ERNST RANK

In many extended versions of the finite element method (FEM) the mesh does not conform to the physical domain. Therefore, discontinuity of variables is expected when some elements are cut by the boundary. Thus, the integrands are not continuous over the whole integration domain. Apparently, none of the well developed integration schemes such as Gauss quadrature can be used readily. This paper investigates several modifications of the Gauss quadrature to capture the discontinuity within an element and to perform a more precise integration. The extended method used here is the finite cell method (FCM), an extension of a high-order approximation space with the aim of simple meshing. Several examples are included to evaluate different modifications.


2015 ◽  
Vol 15 (07) ◽  
pp. 1540018 ◽  
Author(s):  
M. Elhaddad ◽  
N. Zander ◽  
S. Kollmannsberger ◽  
A. Shadavakhsh ◽  
V. Nübel ◽  
...  

In this contribution, the finite cell method (FCM) is applied to solve transient problems of linear elastodynamics. The mathematical formulation of FCM for linear elastodynamics is presented, following from the weak formulation of the initial/boundary-value problem. Semi-discrete time integration schemes are briefly discussed, and the choice of implicit time integration is justified. A 1D benchmark problem is solved using FCM, illustrating the method's ability to solve problems of linear elastodynamics obtaining high rates of convergence. Furthermore, a numerical example of transient analysis from an industrial application is solved using FCM. The numerical results are compared to the results obtained using state-of-the-art commercial software, employing linear finite elements, in conjunction with explicit time integration. The results illustrate the potential of FCM as a powerful tool for transient analysis in elastodynamics, offering a high degree of accuracy at a moderate computational effort.


PAMM ◽  
2015 ◽  
Vol 15 (1) ◽  
pp. 207-208 ◽  
Author(s):  
Meysam Joulaian ◽  
Nils Zander ◽  
Tino Bog ◽  
Stefan Kollmannsberger ◽  
Ernst Rank ◽  
...  

Author(s):  
Benjamin Wassermann ◽  
Nina Korshunova ◽  
Stefan Kollmannsberger ◽  
Ernst Rank ◽  
Gershon Elber

AbstractThis paper proposes an extension of the finite cell method (FCM) to V-rep models, a novel geometric framework for volumetric representations. This combination of an embedded domain approach (FCM) and a new modeling framework (V-rep) forms the basis for an efficient and accurate simulation of mechanical artifacts, which are not only characterized by complex shapes but also by their non-standard interior structure. These types of objects gain more and more interest in the context of the new design opportunities opened by additive manufacturing, in particular when graded or micro-structured material is applied. Two different types of functionally graded materials (FGM) are considered: The first one, multi-material FGM is described using the inherent property of V-rep models to assign different properties throughout the interior of a domain. The second, single-material FGM—which is heterogeneously micro-structured—characterizes the effective material behavior of representative volume elements by homogenization and performs large-scale simulations using the embedded domain approach.


2021 ◽  
Vol 386 ◽  
pp. 114075
Author(s):  
J. Jomo ◽  
O. Oztoprak ◽  
F. de Prenter ◽  
N. Zander ◽  
S. Kollmannsberger ◽  
...  

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