bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Two‐Dimensional Computational Droplet Contact Model
Authors: Osman Muhammad , Sauer Roger A. 
Published: December 2011

AbstractThe interaction between capillary fluid films and micro‐structural rough surfaces is one of the main challenges in studying self‐cleaning mechanisms. The surface behavior of the deformable fluid film is governed by the Young‐Laplace equation, which is highly non‐linear. Therefore, a numerical solution is introduced using the finite element method, based on a continuum mechanical formulation. Surface and line contact at the fluid‐structure interface are modeled by enforcing a contact constraint, and a contact angle, respectively. The numerical solution is validated against the analytical solution of a test case. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical study of human dolphin swimming
Authors: Pacholak Steffen , Rudert Alexander , Brücker Christoph 
Published: December 2011

AbstractPropulsion at human dolphin swimming is gained by performing an undulatory motion through the hole body. This movement is similar to undulatory fish motion. Special physical properties like stiffness of upper and lower extremity parts are creating significant unsteady vortex structures around the hole swimmer when performing dolphin kick. The characteristic of these structures and their influence at propulsion are not very well investigated yet. The present paper discribes the creation of a realistic model using data scans of a female swimmer. It is updated with her unique dolphin motion to simulated complete swim motion. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of the Finite Cell Method to patient‐specific femur simulations
Authors: Ruess Martin , Yosibash Zohar , Trabelsi Nir , Rank Ernst 
Published: December 2011

AbstractStandard methods for predicting the mechanical response of a human femur bone from quantitative computer‐tomography (qCT) scans are classically based on the h‐version of the finite element method. These methods are often limited in accuracy and efficiency due to the need for segmentation and the slow convergence rate. With the Finite Cell Method (FCM) a high‐order fictitious domain method has been developed that overcomes the aforementioned problems and provides accurate results when compared to high‐order finite element methods and experimental results. Herein the FCM applied to the analysis of a patient‐specific femur is presented. The femur model is determined based on qCT‐scans and the elastic response under compression is presented in terms of strains and displacements. The results are compared with a p‐FE analysis and validated by results from an in‐vitro test of the modeled femur. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A micro‐sphere‐based remodelling formulation for arterial tissue including residual stresses
Authors: Waffenschmidt Tobias , Menzel Andreas 
Published: December 2011

AbstractAn essential property of soft biological tissues is the ability to adapt according to respective loading conditions, e.g. by means of fibre reorientation (remodelling). In particular with regard to arterial tissue, an externally unloaded state of the material is generally associated with residual stresses. In this contribution a three‐dimensional micro‐sphere‐based constitutive model for anisotropic soft biological tissue is presented, which includes fibre‐reorientation‐related remodelling as well as residual stress‐effects. As a key aspect of this contribution, time‐dependent remodelling effects are incorporated by introducing evolution equations for the integration directions of the micro‐sphere scheme, which thereby characterize the material's anisotropic properties. An appropriate remodelling approach for the orthotropic case is discussed, whereas the effect of residual stresses is additionally included in the model by means of a multiplicative decomposition of the deformation gradient tensor. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Passive muscle behaviour – experimental and numerical investigations
Authors: Weichert Christine , Leichsenring Kay , Siebert Tobias , Böl Markus 
Published: December 2011

AbstractThe material behaviour of skeletal muscles can be decomposed into two parts: an active part, describing the contractile mechanisms, and a passive one, characterising the passive components such as the connective tissue. Computational models are used to support the understanding of complex mechanism inside a muscle. In the present work, we focus on the three‐dimensional passive tissue behaviour from the experimental as well as modelling point of view. Therefore, quasi‐static experiments have been performed on specimens with regular geometry. By using a three‐dimensional optical measurement system the shape of the specimens has been reconstructed at different deformation states. On the modelling side a hyperelastic model with transversal isotropic fibre orientation has been used to describe non‐linear stress responses. The model has been validated by performing analyses for different fibre orientations. In summary, it figures out that the proposed modelling approach is able to reflect the experimental results in a satisfying manner. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling and Simulation of Multiple Cracking in Textile Reinforced Concrete Tension Specimen using Fracture Mechanics Approaches
Authors: Azzam Aussama , Richter Mike 
Published: December 2011

AbstractThis paper concerns with the finite element simulation of textile reinforced concrete (TRC) behavior under tension loading by using discrete cracking concept and fracture mechanics approaches. 3D Finite‐Element models are formulated on the meso‐scale by simulating all the heterogeneous structural components, the matrix, the fibers, and the fracture mechanisms in both fiber‐matrix interface, and the discrete cracks of the matrix. The presented numerical simulation in this study allows for better understanding of the stress distribution and the interaction between all damage mechanisms and the corresponding energy dissipations. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A BEM for transient thermoelastic fracture analysis of FGMs
Authors: Ekhlakov Alexander , Khay Oksana , Zhang Chuanzeng , Gao Xiao‐Wei 
Published: December 2011

AbstractA boundary element method for the transient thermoelastic fracture analysis in isotropic, continuously non‐homogeneous and linear elastic functionally graded materials subjected to a thermal shock is presented. The material parameters are assumed to be continuous functions of the Cartesian coordinates. Laplace‐domain fundamental solutions of linear coupled thermoelasticity for infinite, isotropic, homogeneous and linear elastic solids are applied to derive the boundary‐domain integral equation formulation. The numerical implementation is performed by using a collocation method for the spatial discretization. Numerical results for the dynamic stress intensity factors are presented and discussed. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of interfacial damage and delamination of sprayed coatings with cohesive elements
Authors: Roth Stephan , Kuna Meinhard 
Published: December 2011

AbstractDelamination of thermally sprayed corrosion protection coatings as a consequence of thermo‐mechanical fatigue is investigated. This study focusses on the modelling of interfacial damage initiation and evolution under cyclic loading with the help of a cohesive zone model. The presented model features a slight non‐linearity at unloading from the exponential “damage locus” as well as cyclic damage accumulation restricted to (re)loading conditions. Additionally, an endurance limit is introduced indicating the maximum sustainable traction for an infinite number of load cycles. The capability of the model is demonstrated. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Delamination of Grain‐Interfaces in Silicon Nitride
Authors: Wippler Johannes , Böhlke Thomas 
Published: December 2011

AbstractIntergranular cracking due to delamination of grain interfaces along with the development of bridging grains is the most important mechanism for the high fracture toughness of silicon nitride. In this line, an interface behavior, which is extending the Coulomb friction concept into the tensile domain has been implemented into a thermodynamical consistent frame work of Helmholtz free energy and dissipation. The model is used to describe the fracture process in a simple model geometry with a β‐Si3N4 grain embedded into a precracked matrix of oxynitride glass. The material model considers the thermoelastic anisotropy of the grain and the thermal residual stresses, which evolve during the cooling of the model from the glass transition temperature to room temperature. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analytical stress analysis of partially plastic graded curved bars subjected to pure bending
Authors: Arslan Eray , Eraslan Ahmet N. 
Published: December 2011

AbstractAn analytical model is developed to analyze stresses in functionally graded (FGM) curved bars under pure bending. Both elastic and partially plastic stress states are considered. The modulus of elasticity of the bar material is allowed to vary. While the model is outlined, important findings are mentioned. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mechatronic Subsystem Studied of Approximate Method Modeled by Hypergraph
Authors: Buchacz Andrzej 
Published: December 2011

AbstractThe transverse vibrating mechatronic subsystem is considered. Integral parts of this system are: a continuous beam with known boundary conditions and a transducer, extorted by harmonic voltage excitation, to be perfectly bonded to the beam surface. Findings this article are dynamical characteristics of the discussed mechatronic and mechanical system to model them by hypergraphs. Research limitation is that the linear mechanical subsystem and linear electric subsystem of mechatronic system has been considered, however for this kind of systems the approach is sufficient. Practical implications of this researches was that global approach is presented, that means in the domain of frequency spectrum analysis. The methods of analysis and obtained results can be base of design and investigation for this type of mechatronic systems. Originality of this paper is that the mechatronic system created from mechanical and electric subsystems with electromechanical bondage has been considered. This approach is different from those considered so far because is it relies on application approximate methods of analysis of mechatronic subsystem and modeling the one by hypergraph [1‐7]. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Consistent time integration for transient three‐dimensional contact using the NTS‐method
Authors: Franke Marlon , Hesch Christian , Betsch Peter 
Published: December 2011

AbstractThe present work aims to investigate stable time integrators for large deformation contact problems within the framework of the well known node‐to‐segment (NTS)‐method. For this kind of problem, standard time integrators fail to conserve the total energy of the system. To remedy this drawback, we combine a mixed method with the concept of a discrete gradient applied to the aforementioned NTS‐method. In the context of nonlinear elastodynamics stable integrators for ordinary differential equations have been extensively developed and investigated during the last two decades. For contact problems, energy consistent integrators have been developed for the NTS‐method (see e.g. Ref. [1]). (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elastic‐plastic halfspace simulation
Authors: Hauer Franz , Willner Kai 
Published: December 2011

AbstractDue to the roughness of technical surfaces only the surface peaks are in contact for moderate contact pressures. Thus, the real contact area is smaller than the apparent contact area. Contact forces can only occur in the real contact area. Consequently it is necessary to determine the deformation of surface asperities in order to analyse the tribological properties of surfaces. The real contact area is usually small in initial contact. This leads to large contact pressures which in turn lead to the plastic deformation of surface roughness peaks. Therefore an elastic‐plastic model is necessary. The halfspace model seems to be beneficial because there is only a system of equations on a surface mesh to be solved and not on a volume mesh like in the Finite‐Element‐Method. This leads to a much smaller system of equations which should allow reasonable calculation times even for large contact surfaces. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Buckling Analysis of Carbon Nanotubes – a molecular mechanics approach using the finite element framework
Authors: Hollerer Stefan 
Published: December 2011

AbstractIn this work, a molecular mechanics model embedded in the finite element framework is applied to analyze the buckling behaviour of carbon nanotubes. Within this model a specific finite element is set up for the underlaying interatomic potential describing the behaviour of the multi particle system. The model relies on the fully nonlinear description of the interatomic potential and the atomic kinematics. Stability points of the system are located by an accompanying eigenvalue analysis and the bifurcation point is detected using a bisection algorithm. To follow the nonlinear load‐deformation path in the area of postbuckling a branch switch is performed. With the help of this molecular mechanics model, the response of carbon nanotubes on different loading conditions with respect to buckling is studied. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic Stability Analysis of Shells Using a Finite Element Based Reduction Method
Authors: Jansen Eelco , Rahman Tanvir , Gürdal Zafer 
Published: December 2011

AbstractA finite element formulation of a reduction method for dynamic stability analysis of imperfection‐sensitive shell structures is presented. The reduction method makes use of a perturbation approach, initially developed for static buckling and later extended to dynamic buckling analysis. The single mode dynamic buckling analysis and its extension to parametric excitation analysis are described. The approach is available within a general purpose finite element code. Characteristic results for the parametric excitation analysis of a composite cylindrical shell are shown. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of material and structural inhomogeneities in timber structures
Authors: Jenkel Christian , Lang Ronny , Kaliske Michael 
Published: December 2011

AbstractThe numerical simulation of timber structures by means of FEM has been an object of recent research. Most of the material models developed so far are based on idealized assumptions by disregarding inhomogeneities. Here, models to capture structural inhomogeneities in terms of branches and knots and the resulting deviation in grain course in a three‐dimensional FE analysis are presented. Besides, naturally varying material properties referred to as material inhomogeneities have to be considered in the structural analysis. Due to the insufficient experimental data, the uncertainty model fuzziness is applied. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of PID Control Unit for System Stabilization in Process‐integrated Powder Coating by Radial Axial Rolling of Rings
Authors: Kebriaei Reza , Frischkorn Jan , Reese Stefanie 
Published: December 2011

AbstractThe process integrated powder coating by radial axial rolling of rings represents a new hybrid production technique in order to apply the functional layers on ring‐shaped work pieces. Since the layer is produced in a powder metallurgical way [1], the ring volume decreases during the compaction of the layer material. In conventional ring rolling processes an isochoric plastic deformation of the ring is exploited in order to control the process. However this is not true any more for a ring exhibiting a compressible layer [2]. Consequently different control mechanisms have to be developed for the new considered process. One major aspect is the stability of the process which is governed by a stable position of the ring as well as the roundness of the ring. Therefore the finite element (FE) model has been coupled with a PID‐controller unit and it will be shown that a stable process can be reached in this way. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asymptotic analysis of the interaction of a finite number of holes in an elastic plane or half‐plane
Authors: Kratochvil Jan , Becker Wilfried 
Published: December 2011

AbstractThe problem of the interaction of a finite number of holes in an elastic plane or half‐plane is considered. The analysis is based on the complex potential method of Muskhelishvili as well as on the theory of compound asymptotic expansions by Maz'ya. An asymptotic expansion of the complex potentials in terms of relative hole radii is constructed. This expansion is uniformly valid in the whole domain. The method leads to a simple procedure which does not involve any coupled system of linear equations. The successive closed‐form approximations can be obtained in an iterative manner to an arbitrary order without any need for numerical approximation. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Symmetric Galerkin Boundary Element Method for Linear Poroelasticity
Authors: Messner Michael , Schanz Martin 
Published: December 2011

AbstractIn linear poroelasticity so far only collocation boundary element methods have been available. However, in some applications, e.g., when coupling with finite elements is desired, a symmetric formulation is preferable. Choosing a Galerkin approach which involves the second boundary integral equation, such a formulation is possible. Here, a previously presented integration by part technique for the regularization of the first boundary integral equation is extended to the second boundary integral equation as well. While the weakly singular representation of the double layer operator has been presented before, the emphasis lies here on the so called hyper‐singular boundary integral operator. Due to the regularization, this operator can be evaluated numerically and, hence, be used within a numerical scheme for the first time. Different numerical studies will be presented to show the behavior of the established symmetric Galerkin boundary element method, also comparing it with collocation boundary element methods. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Finite Element implementation for the EULER‐EYTELWEIN‐problem and further use in FEM‐simulation of common nautical knots
Authors: Metzger Andreas , Konyukhov Alexander , Schweizerhof Karl 
Published: December 2011

AbstractThe computation of ropes and cable constructions considering contact as well as friction is often required in engineering practice. That includes mutual frictional contact between two and more ropes and frictional contact between ropes and solid –mostly assumed as rigid– bodies. The latter occurs especially in the mechanical model of a rope wound around a cylinder. So the main topic of this contribution is the development and FE‐implementation of a "Segment‐ To‐Analytical‐Surface (STAS)"‐contact‐element which can be used to describe the mechanical model of a rope wound around a cylinder. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear failure mechanisms of laminated composites
Authors: Völlmecke Christina , Müller Wolfgang H. 
Published: December 2011

AbstractTwo distinct analytical models are described representing geometrically nonlinear instabilities in layered composites under in‐plane compression — kink‐banding and delamination buckling. The utilized technique is based on of energy minimization principles in order to examine the underlying mechanics of the systems. It is demonstrated that using this approach enables investigations to be undertaken far into the postbuckling range whilst changing system parameters. Thereby a greater phenomenological understanding of the mechanics of the systems is achieved. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A comparison of time adaptive integration methods for small and large strain viscoelasticity
Authors: Rothe Steffen , Hartmann Stefan , Hamkar Ahmad‐Wahadj , Quint Karsten 
Published: December 2011

AbstractIn quasistatic solid mechanics the initial boundary value problem has to be solved in the space and time domain. The spatial discretization is done using finite elements. For the temporal discretization three different classes of Runge‐Kutta methods are compared. These methods are diagonally implicit Runge‐Kutta schemes (DIRK), linear implicit Runge‐Kutta methods (Rosenbrock type methods) and half‐explicit Runge‐Kutta schemes (HERK). It will be shown that the application of half‐explicit or linear‐implicit Runge‐Kutta methods can enormously reduce the computational time in particular situations. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On Neumann ‐ Dirchlet coupling strategy of Finite Element and Boundary Element method in elastodynamics
Authors: Rurkowska Katherina , Schauer Marco , Langer Sabine 
Published: December 2011

AbstractThe Finite Element Method (FEM) and the Boundary Element Method (BEM) are the most used numerical tools for solid mechanics analysis. Each one of these methods has advantages and drawbacks in different cases. In order to take advantage of both methods, a nonoverlapping domain decomposition method FEM ‐ BEM in elastodynamics is presented. The domain is divided in two subdomains and each one of them is analyzed separately and only the interface information is exchanged. An iterative Neumann ‐ Dirchlet algorithm with relaxation is used, to get continuity and the equilibrium conditions at the interface. The FEM time integration is carried out using the Newmark's method and the BEM approach in time domain is based in the Convolution Quadrature Method developed by Lubich. Numerical examples are presented to show agreement with other available numerical results. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Finite Cell Method for large deformation analysis
Authors: Schillinger Dominik , Ruess Martin , Düster Alexander , Rank Ernst 
Published: December 2011

AbstractThe Finite Cell Method (FCM) combines the fictitious domain approach with high‐order finite elements and adaptive integration. For linear elastic problems with smooth solution, FCM has been shown to achieve exponential rates of convergence in energy norm, while its structured cell grid guarantees simple mesh generation irrespective of the geometric complexity involved. In this contribution, the FCM idea is combined with standard finite element technology for the solution of geometrically nonlinear problems. In particular, a modified FCM formulation is introduced, which resets the deformed configuration of the fictitious domain to the deformation‐free reference configuration after each Newton iteration. Numerical experiments show that this intervention allows for stable nonlinear FCM analysis with very small values of the penalty parameter, while the accuracy of the geometrically nonlinear solution within the physical domain remains unaffected. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)