Refine
Year of publication
Document Type
- Article (132)
- Conference Proceeding (62)
- Part of a Book (13)
- Book (4)
- Lecture (3)
- Other (3)
- Report (2)
- Doctoral Thesis (1)
- Patent (1)
- Review (1)
Keywords
- Finite-Elemente-Methode (16)
- Einspielen <Werkstoff> (13)
- shakedown analysis (9)
- FEM (6)
- Limit analysis (6)
- Shakedown analysis (6)
- limit analysis (6)
- Einspielanalyse (4)
- Shakedown (4)
- Technische Mechanik (4)
- Traglast (4)
- Traglastanalyse (4)
- shakedown (4)
- ratchetting (3)
- Analytischer Zulaessigkeitsnachweis (2)
- Biocomposites (2)
- Bruchmechanik (2)
- Druckbeanspruchung (2)
- Druckbehälter (2)
- Druckbelastung (2)
- Einspiel-Analyse (2)
- Fehlerstellen (2)
- Natural fibres (2)
- Polymer-matrix composites (2)
- Ratcheting (2)
- Rohr (2)
- Rohrbruch (2)
- Stahl (2)
- Stress concentrations (2)
- burst pressure (2)
- burst tests (2)
- damage (2)
- flaw (2)
- limit load (2)
- load limit (2)
- pipes (2)
- tension–torsion loading (2)
- vessels (2)
- Alternating plasticity (1)
- Anastomose (1)
- Anastomosis (1)
- Anastomotic leakage (1)
- Arthosetherapie (1)
- Aufschlagversuch (1)
- Autolysis (1)
- Axialbelastung (1)
- Axially cracked pipe (1)
- Basis Reduktion (1)
- Basis reduction (1)
- Bicharakteristikenverfahren (1)
- Biomechanics (1)
- Biomechanik (1)
- Biomedizinische Technik (1)
- Bladder (1)
- Bone sawing (1)
- Cardiac myocytes (1)
- Cardiac tissue (1)
- CellDrum (1)
- Chance constrained programming (1)
- Collagen fibrils (1)
- Computational biomechanics (1)
- Connective tissues (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)
- Druckgeräte (1)
- Drug simulation (1)
- ES-FEM (1)
- Einspiel-Kriterium (1)
- Einspielen (1)
- Elastizität (1)
- Elastodynamik (1)
- Elastostatics (1)
- Electromechanical modeling (1)
- End-to-end colorectal anastomosis (1)
- Evolution of damage (1)
- Exact Ilyushin yield surface (1)
- Extension fracture (1)
- Extension strain criterion (1)
- Extracellular matrix (ECM) (1)
- FEM-Programm (1)
- FEM-computation (1)
- FS-FEM (1)
- Festkörper (1)
- Finite element analysis (1)
- Finite element analysis (FEA) (1)
- Finite element method (1)
- Finite element modelling (1)
- First Order Reliabiblity Method (1)
- First-order reliability method (1)
- Fließgrenze (1)
- Freeze–thaw process (1)
- Frequency adaption (1)
- Fußball (1)
- Global and local collapse (1)
- Gonarthrose (1)
- Grenzwertberechnung (1)
- Growth modelling (1)
- Heart tissue culture (1)
- Hodgkin–Huxley models (1)
- Homogenization (1)
- Induced pluripotent stem cells (1)
- Inotropic compounds (1)
- Ion channels (1)
- Kinematics (1)
- Kinetics (1)
- Kniegelenkarthrose (1)
- Knochen (1)
- Knochenbildung (1)
- Knochenchirugie (1)
- Knochendichte (1)
- LISA (1)
- Liver (1)
- MBST (1)
- Materialermüdung (1)
- Mechanical simulation (1)
- Mechanical stability (1)
- Mechanics (1)
- Mohr–Coulomb criterion (1)
- Multi-dimensional wave propagation (1)
- Multimode failure (1)
- Muscle fibers (1)
- Nichtlineare Gleichung (1)
- Nichtlineare Optimierung (1)
- Nichtlineare Welle (1)
- Non-linear optimization (1)
- Non-parallel fissures (1)
- PFM (1)
- Passive stretching (1)
- Pelvic floor dysfunction (1)
- Pelvic muscle (1)
- Pharmacology (1)
- Plastizität (1)
- Pressure loaded crack-face (1)
- Progressive plastic deformation (1)
- Random variable (1)
- Ratchetting (1)
- Reconstruction (1)
- Reliability analysis (1)
- Reliability of structures (1)
- S-FEM (1)
- Schienbeinschoner (1)
- Schwammknochen (1)
- Sensitivity (1)
- Shakedown criterion (1)
- Spleen (1)
- Sprunggelenkorthesen (1)
- Statics (1)
- Stochastic programming (1)
- Strukturanalyse (1)
- Surgical staplers (1)
- Tapered ends (1)
- Temperaturabhängigkeit (1)
- Torsion (1)
- Torsionsbelastung (1)
- Tragfähigkeit (1)
- Uniaxial compression test (1)
- Ureter (1)
- Variable height stapler design (1)
- Wellen (1)
- Wolff's Law (1)
- Wolffsches Gesetz (1)
- Zug-Druck Belastung (1)
- Zug-Druck-Beanspruchung (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)
- cancellous bone (1)
- chance constrained programming (1)
- constitutive modeling (1)
- dental trauma (1)
- design-by-analysis (1)
- difficult airway (1)
- direct method (1)
- distorted element (1)
- double-lumen tube intubation (1)
- elastic solids (1)
- fatigue analyses (1)
- fibulare Bandruptur (1)
- finite element analysis (1)
- fortschreitende plastische Deformation (1)
- gonarthrosis (1)
- hiPS cardiomyocytes (1)
- hyperelastic (1)
- konvexe Optimierung (1)
- limit and shakedown analysis (1)
- linear kinematic hardening (1)
- load carrying capacity (1)
- lower bound theorem (1)
- material shakedown (1)
- mechanical waves (1)
- non-simplex S-FEM elements (1)
- nonlinear kinematic hardening (1)
- nonlinear optimization (1)
- nonlinear solids (1)
- nonlinear tensor constitutive equation (1)
- plastic deformation (1)
- probabilistic fracture mechanics (1)
- reliability (1)
- reliability analysis (1)
- reliability of structures (1)
- rupture of the fibular ligament (1)
- second-order reliability method (1)
- shakedown analyses (1)
- smooth muscle contraction (1)
- stochastic programming (1)
- strain energy function (1)
- thermal ratcheting (1)
- training simulator (1)
- videolaryngoscopy (1)
- virgin passive (1)
- virtual reality (1)
- viscoelasticity (1)
- yield stress (1)
Direct methods comprising limit and shakedown analysis is a branch of computational mechanics. It plays a significant role in mechanical and civil engineering design. The concept of direct method aims to determinate the ultimate load bearing capacity of structures beyond the elastic range. For practical problems, the direct methods lead to nonlinear convex optimization problems with a large number of variables and onstraints. If strength and loading are random quantities, the problem of shakedown analysis is considered as stochastic programming. This paper presents a method so called chance constrained programming, an effective method of stochastic programming, to solve shakedown analysis problem under random condition of strength. In this our investigation, the loading is deterministic, the strength is distributed as normal or lognormal variables.
Limit and shakedown theorems are exact theories of classical plasticity for the direct computation of safety factors or of the load carrying capacity under constant and varying loads. Simple versions of limit and shakedown analysis are the basis of all design codes for pressure vessels and pipings. Using Finite Element Methods more realistic modeling can be used for a more rational design. The methods can be extended to yield optimum plastic design. In this paper we present a first implementation in FE of limit and shakedown analyses for perfectly plastic material. Limit and shakedown analyses are done of a pipe–junction and a interaction diagram is calculated. The results are in good correspondence with the analytic solution we give in the appendix.
Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal–dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal–dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.
Limit Analysis of Defects
(2000)
The mechanical behavior of the large intestine beyond the ultimate stress has never been investigated. Stretching beyond the ultimate stress may drastically impair the tissue microstructure, which consequently weakens its healthy state functions of absorption, temporary storage, and transportation for defecation. Due to closely similar microstructure and function with humans, biaxial tensile experiments on the porcine large intestine have been performed in this study. In this paper, we report hyperelastic characterization of the large intestine based on experiments in 102 specimens. We also report the theoretical analysis of the experimental results, including an exponential damage evolution function. The fracture energies and the threshold stresses are set as damage material parameters for the longitudinal muscular, the circumferential muscular and the submucosal collagenous layers. A biaxial tensile simulation of a linear brick element has been performed to validate the applicability of the estimated material parameters. The model successfully simulates the biomechanical response of the large intestine under physiological and non-physiological loads.
Kyphoplasty of Osteoporotic Fractured Vertebrae: A Finite Element Analysis about Two Types of Cement
(2019)
Influence of refrigerated storage on tensile mechanical properties of porcine liver and spleen
(2015)
Influence of a freeze–thaw cycle on the stress–stretch curves of tissues of porcine abdominal organs
(2012)
The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze–thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze–thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.