Refine
Year of publication
Document Type
- Article (132) (remove)
Keywords
- Einspielen <Werkstoff> (7)
- FEM (4)
- Finite-Elemente-Methode (4)
- shakedown analysis (3)
- Einspielanalyse (2)
- Shakedown analysis (2)
- Traglastanalyse (2)
- damage (2)
- limit analysis (2)
- shakedown (2)
- Alternating plasticity (1)
- Analytischer Zulaessigkeitsnachweis (1)
- Anastomotic leakage (1)
- Arthosetherapie (1)
- Aufschlagversuch (1)
- Autolysis (1)
- Axialbelastung (1)
- Axially cracked pipe (1)
- Basis Reduktion (1)
- Basis reduction (1)
- Bicharakteristikenverfahren (1)
- Biocomposites (1)
- Cardiac myocytes (1)
- Cardiac tissue (1)
- CellDrum (1)
- Computational biomechanics (1)
- Constitutive model (1)
- Convex optimization (1)
- Damage mechanics theory (1)
- Decomposition (1)
- Deformation (1)
- Design-by-analysis (1)
- Discontinuous fractures (1)
- Distorsion des oberen Sprunggelenks (1)
- Druckbeanspruchung (1)
- Druckbehälter (1)
- Druckbelastung (1)
- Druckgeräte (1)
- Drug simulation (1)
- ES-FEM (1)
- Einspiel-Analyse (1)
- Einspiel-Kriterium (1)
- Einspielen (1)
- Elastizität (1)
- Electromechanical modeling (1)
- End-to-end colorectal anastomosis (1)
- FS-FEM (1)
- Fehlerstellen (1)
- Finite element analysis (1)
- Finite element modelling (1)
- Fließgrenze (1)
- Freeze–thaw process (1)
- Frequency adaption (1)
- Fußball (1)
- Global and local collapse (1)
- Gonarthrose (1)
- Grenzwertberechnung (1)
- Heart tissue culture (1)
- Hodgkin–Huxley models (1)
- Homogenization (1)
- Induced pluripotent stem cells (1)
- Inotropic compounds (1)
- Ion channels (1)
- Kniegelenkarthrose (1)
- Knochen (1)
- Knochenbildung (1)
- Knochenchirugie (1)
- Knochendichte (1)
- Limit analysis (1)
- Liver (1)
- MBST (1)
- Materialermüdung (1)
- Natural fibres (1)
- Non-parallel fissures (1)
- Pharmacology (1)
- Plastizität (1)
- Polymer-matrix composites (1)
- Pressure loaded crack-face (1)
- Progressive plastic deformation (1)
- Ratchetting (1)
- Rohr (1)
- Rohrbruch (1)
- S-FEM (1)
- Schienbeinschoner (1)
- Schwammknochen (1)
- Shakedown (1)
- Shakedown criterion (1)
- Spleen (1)
- Sprunggelenkorthesen (1)
- Stahl (1)
- Stress concentrations (1)
- Strukturanalyse (1)
- Surgical staplers (1)
- Temperaturabhängigkeit (1)
- Traglast (1)
- Uniaxial compression test (1)
- Variable height stapler design (1)
- Wolff's Law (1)
- Wolffsches Gesetz (1)
- Zug-Druck Belastung (1)
- alternierend Verformbarkeit (1)
- anaesthetic complications (1)
- anisotropy (1)
- ankle braces (1)
- ankle sprain (1)
- arthrosis therapy (1)
- biaxial tensile experiment (1)
- bicharacteristics (1)
- bone density (1)
- bone structure (1)
- burst pressure (1)
- burst tests (1)
- cancellous bone (1)
- chance constrained programming (1)
- constitutive modeling (1)
- dental trauma (1)
- difficult airway (1)
- direct method (1)
- distorted element (1)
- double-lumen tube intubation (1)
- elastic solids (1)
- fatigue analyses (1)
- fibulare Bandruptur (1)
- flaw (1)
- fortschreitende plastische Deformation (1)
- gonarthrosis (1)
- hiPS cardiomyocytes (1)
- hyperelastic (1)
- konvexe Optimierung (1)
- limit load (1)
- load limit (1)
- non-simplex S-FEM elements (1)
- pipes (1)
- ratchetting (1)
- reliability analysis (1)
- reliability of structures (1)
- rupture of the fibular ligament (1)
- shakedown analyses (1)
- smooth muscle contraction (1)
- stochastic programming (1)
- strain energy function (1)
- tension–torsion loading (1)
- thermal ratcheting (1)
- vessels (1)
- videolaryngoscopy (1)
- virgin passive (1)
- viscoelasticity (1)
- yield stress (1)
Institute
Wind is closely associated with the discussion of fairness in ski jumping. To counter-act its influence on the jump length, the International Ski Federation (FIS) has introduced a wind compensation approach. We applied three differently accurate computer models of the flight phase with wind (M1, M2, and M3) to study the jump length effects of various wind scenarios. The previously used model M1 is accurate for wind blowing in direction of the flight path, but inaccuracies are to be expected for wind directions deviating from the tangent to the flight path. M2 considers the change of airflow direction, but it does not consider the associated change in the angle of attack of the skis which additionally modifies drag and lift area time functions. M3 predicts the length effect for all wind directions within the plane of the flight trajectory without any mathematical simplification. Prediction errors of M3 are determined only by the quality of the input data: wind velocity, drag and lift area functions, take-off velocity, and weight. For comparing the three models, drag and lift area functions of an optimized reference jump were used. Results obtained with M2, which is much easier to handle than M3, did not deviate noticeably when compared to predictions of the reference model M3. Therefore, we suggest to use M2 in future applications. A comparison of M2 predictions with the FIS wind compensation system showed substantial discrepancies, for instance: in the first flight phase, tailwind can increase jump length, and headwind can decrease it; this is opposite of what had been anticipated before and is not considered in the current wind compensation system in ski jumping.
Virgin passive colon biomechanics and a literature review of active contraction constitutive models
(2022)
The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel–Gasser–Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill’s three-element model, Murphy’s four-state cross-bridge chemical kinetic model and Huxley’s sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.
Zusammenfassung: In der Orthopädie zählt der therapeutische Ultraschall als Mittel zur Prävention und Therapiebegleitung. Er hat mechanische, thermische und physiko-chemische Auswirkungen auf den menschlichen Körper. Um mehr Erkenntnisse über die thermischen Auswirkungen zu erlangen, wurden Versuche an einem Hydrogel-Phantom und an Probanden durchgeführt. Dabei entstand eine signifikante Erwärmung des Gewebes, welche beim Probandenversuch an der Oberfläche und beim Hydrogelversuch in der Tiefe gemessen wurde.
Summary: In orthopaedics, therapeutic ultrasound is a tool of prevention and therapy support. It has mechanical, thermal and physico-chemical effects on the human body. Tests with a hydrogel phantom and with human probands have been performed in order to obtain more knowledge about their thermal effects. Both tests measured temperature increases in cell tissue, on the surface with the human proband test and in depth with the hydrogel phantom test.