Article
Refine
Year of publication
- 2024 (1)
- 2022 (6)
- 2021 (3)
- 2020 (8)
- 2019 (9)
- 2018 (10)
- 2017 (4)
- 2016 (7)
- 2015 (3)
- 2014 (2)
- 2013 (7)
- 2012 (6)
- 2011 (1)
- 2010 (6)
- 2009 (2)
- 2008 (5)
- 2007 (4)
- 2006 (1)
- 2005 (2)
- 2004 (3)
- 2003 (3)
- 2002 (2)
- 2000 (3)
- 1999 (2)
- 1998 (1)
- 1997 (2)
- 1996 (2)
- 1995 (1)
- 1993 (3)
- 1992 (1)
- 1991 (2)
- 1990 (1)
- 1989 (1)
- 1988 (1)
- 1987 (1)
- 1985 (1)
Document Type
- Article (117) (remove)
Has Fulltext
- no (117) (remove)
Keywords
- damage (2)
- Anastomotic leakage (1)
- Autolysis (1)
- Biocomposites (1)
- Cardiac myocytes (1)
- Cardiac tissue (1)
- CellDrum (1)
- Computational biomechanics (1)
- Constitutive model (1)
- Damage mechanics theory (1)
- Decomposition (1)
- Discontinuous fractures (1)
- Distorsion des oberen Sprunggelenks (1)
- Drug simulation (1)
- ES-FEM (1)
- Electromechanical modeling (1)
- End-to-end colorectal anastomosis (1)
- FS-FEM (1)
- Finite element analysis (1)
- Finite element modelling (1)
Institute
Edge-based and face-based smoothed finite element methods (ES-FEM and FS-FEM, respectively) are modified versions of the finite element method allowing to achieve more accurate results and to reduce sensitivity to mesh distortion, at least for linear elements. These properties make the two methods very attractive. However, their implementation in a standard finite element code is nontrivial because it requires heavy and extensive modifications to the code architecture. In this article, we present an element-based formulation of ES-FEM and FS-FEM methods allowing to implement the two methods in a standard finite element code with no modifications to its architecture. Moreover, the element-based formulation permits to easily manage any type of element, especially in 3D models where, to the best of the authors' knowledge, only tetrahedral elements are used in FS-FEM applications found in the literature. Shape functions for non-simplex 3D elements are proposed in order to apply FS-FEM to any standard finite element.
Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.
Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis
(2016)
Background
Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far.
Methods
10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed.
Findings
Compared to the control group, the work to fracture could be increased by 33.2%. The fracture force increased by 19.9%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry.
Interpretation
The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results.