bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical modelling of the in‐plane compressive behaviour of pile fibres in Spacer Fabric Composites
Authors: Köllner Anton , Völlmecke Christina 
Published: December 2014

AbstractThe mechanical behaviour of Spacer Fabric Composites (SFC) is highly influenced by their pile fibres. Within this work, the in‐plane compressive behaviour of pile fibres in SFC is investigated. An analytical model is developed based on rigid hinged struts. Therefore, a representative part of the continuous fibre is chosen. The bending behaviour and the interaction of the pile fibre with facesheet fibres is modelled using rotational and extension springs respectively. The system proposed is fully defined by three generalized coordinates. The total potential energy of the system is determined and used to obtain information about the deformation behaviour. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analytical modelling of nonlinear buckling of (de‐)laminated composite struts
Authors: Völlmecke Christina 
Published: December 2014

AbstractLaminated fibre‐reinforced composites are prone to delamination damage. This interlaminar defect lowers the critical buckling load of a strut and may lead to unstable postbuckling. Thus, the critical load of laminated and delaminated struts are the topic of investigation herein. Small scale experimental investigations were undertaken and comparison is sought with analytical formulations whilst a model for a delaminated strut is introduced. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Passive damping of bridge vibrations by tuned liquid column gas dampers
Authors: Ziegler Franz 
Published: December 2014

AbstractSealed tuned liquid column gas dampers, i.e. with a gas spring effect taken into account, TLCGD, are ideally suited to increase the effective structural damping of bridges when vibrating in the critical low frequency band, substituting the classical mechanical damper (TMD). The evident features of TLCGD are no moving mechanical parts, cheap and easy implementation, low maintenance costs and simple modification of the natural frequency (by means of altering the equilibrium gas pressure). Modal tuning in analogy to the classical mechanical damper, TMD, in the design stage is subsequently followed by fine‐tuning in state space, rendering the absorber parameter (frequency and damping) optimal and, when designing smaller units in parallel action, yields the control even more robust. The equilibrium gas‐pressure is the main control parameter to optimize the absorber frequency when the volume of the individual gas vessel above the liquid‐gas interface is properly selected. U‐ or V‐shaped TLCGD with horizontal extension maximized, are proposed to reduce dominating horizontal vibrations of long‐span bridges (including pedestrian bridges), and in the case of the cantilever method of bridge construction to allow the increase of the maximum length of the cantilever, despite of wind‐gusts. An alternate design, VTLCGD provides the control force vertically, and thus counteracts dominating vertical, traffic‐induced vibrations. The horizontal length of the absorber is kept to a minimum. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Galerkin‐based multi‐scale time integration for nonlinear structural dynamics
Authors: Bartelt Matthias , Groß Michael 
Published: December 2014

AbstractThis paper deals with a GALERKIN‐based multi‐scale time integration of a viscoelastic rope model. Using HAMILTON's dynamical formulation, NEWTON's equation of motion as a second‐order partial differential equation is transformed into two coupled first order partial differential equations in time. The considered finite viscoelastic deformations are described by means of a deformation‐like internal variable determined by a first order ordinary differential equation in time. The corresponding multi‐scale time‐integration is based on a PETROV‐GALERKIN approximation of all time evolution equations, leading to a new family of time stepping schemes with different accuracy orders in the state variables. The resulting nonlinear algebraic time evolution equations are solved by a multi‐level NEWTON‐RAPHSON method. Realizing this transient numerical simulation, we also demonstrates a parallelized solution of the viscous evolution equation in CUDA©. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Krylov Subspace Reduced‐Order Modeling Methods for Structural Dynamic Finite Element Systems
Authors: Tegtmeyer Stefanie , Nackenhorst Udo 
Published: December 2014

AbstractComputational resources can be used more efficiently by introducing reduced‐order models, instead of solving large systems of equations of the original model. In this contribution, the Krylov subspace method, a reduced‐order modeling method, is studied and compared to the modal decomposition for a rubber wheel model. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal stresses in a cylindrical panel with free ends
Authors: Haskul Mehmet , Arslan Eray 
Published: December 2014

AbstractElastic stress state of a thick‐walled cylindrical panel, which is subjected to a positive temperature gradient in the radial direction, is investigated under generalized plane strain conditions. In particular, the stress distributions in the panel at the elastic limit according to von Mises' yield criterion are studied. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extension of the scaled boundary finite element method to geometrical and physical nonlinearity
Authors: Behnke Ronny , Mundil Matthias , Birk Carolin , Kaliske Michael 
Published: December 2014

AbstractThe scaled boundary finite element method (SBFEM) has been used in many fields of engineering to solve the governing equations in bounded and unbounded 2D as well as 3D domains. In solid mechanics, the semi‐analytical solution strategy of the SBFE formulation (numerical in circumferential direction, analytical in radial direction) is based on the assumption of linear elastic material behavior and only small geometrical changes. However, a large group of materials (e.g. rubber) shows geometrical and physical nonlinearity at mechanical loading. In this contribution, the extension of the SBFEM to geometrical and physical nonlinearity is examined. A plane finite element is developed which uses the concept of shape functions constructed by the SBFEM in the framework of a nonlinear finite element analysis. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of Uncertain Inelastic Material Behaviour using the Stochastic Finite Element Method
Authors: Fink Sebastian , Nackenhorst Udo 
Published: December 2014

AbstractIn this work, an approach for computing three‐dimensional structures with random material properties, such as the yield stress, Young's modulus and hardening parameters is proposed. The random material properties are represented as random fields which are realized with the Spectral Representation Method (SPRM). The proposed approach is coupled with Monte Carlo Simulation (MCS) to determine the response statistics of a simple mechanical structure. The numerical results are compared with those obtained from classical Latin Hypercube Sampling (LHS). (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SBFEM elements for thin‐walled composite beams with arbitrary layup
Authors: Jung Jonathan Daniel , Becker Wilfried 
Published: December 2014

AbstractThe scaled boundary finite element method (SBFEM) is a semi‐analytical method in which only the boundary is discretized. The results on the boundary are scaled into the domain with respect to a scaling center which must be “visible” from the whole boundary. For beam‐like problems the scaling center can be selected at infinity and only the cross‐section is discretized. Two new elements for thin‐walled beams have been developed on the basis of the first order shear deformation theory. The beam sections are considered to be multilayered laminate plates with arbitrary layup. The arbitrary cross‐section is discretized with beam elements of Timoshenko type. Using the virtual work principle gives the SBFEM equation, which is a system of differential equations of a gyroscopic type. The solution is calculated using the matrix exponential function. The elements have been tested and compared with a finite element model and they give good results. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active influence on friction contacts in larger objects
Authors: Hammerschmidt Antonia , von Wagner Utz , Kracht Kerstin 
Published: December 2014

AbstractUltrasonic vibrations in the micrometer amplitude range have been proven to be capable to influence frictional contacts with respect to decreasing friction coefficients in experiments on small test set‐ups solely loaded by their small weight. The question is, if these effects can also be found in larger objects. This paper shows results of experimental work on applying this effect to larger objects and lager normal loads. Special focus is layed on the contact between the wheel and the rail, while the wheel or the rail being excited by piezoceramics or shakers respectively. To get the largest possible vibration amplitudes, the wheels are designed using FE‐models and are experimentally investigated for optimal actor placing and excitation by modal analysis. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the hydraulic fluid pipe on the dynamic stability of a shift gearbox
Authors: Jehle Georg , Fidlin Alexander 
Published: December 2014

AbstractShift gearboxes are used in vehicle drive trains in order to transmit the driving torque of the motor and to shift between different transmission ratios. Because of the occurrence of sliding friction forces and ‐torques during the shifting period, unwanted vibrations can arise. Several mechanisms which lead to a destabilization of the stationary state in shift gearboxes are conceivable: variable friction coefficient [1], wobbling clutch disc [2], or vibrations because of coupled DoFs due to the helical gearing [3].The latter effect results in translational oscillations in axial and radial direction of the clutch disc. It was observed that damping forces influence the boundary of the region of stability in the parameter space ‐ though it is not entirely clear where such forces originate from. For this reason, in this work the effect of the fluid of the hydraulic actuation of the clutch system is analyzed. The fluid pipe is situated in the center of the gear unit input shaft and forces the fluid to oscillate when the system becomes unstable. In return, the fluid implies shear stress and pressure on the adjacent mechanical parts (shaft, pressure plates). The analysis of the stationary state of the coupled system reveals a clear effect of fluid properties on the stability: both the mass density and the kinematic viscosity are able to change the location of the border between stable and instable regions in the parameter space. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Arclength Continuation Methods for the Investigation of Non‐linear Oscillating Systems with the Concept of Non‐linear Normal Modes
Authors: Jerschl Martin , Willner Kai 
Published: December 2014

AbstractNon‐linear normal modes (NNMs) can be considered as a non‐linear analogon to the description of linear systems with linear normal modes (LNMs). The definition of NNMs can be found in [1]. Small systems with a low number of degrees of freedom and non‐linear couplings (cubic springs) are investigated here. With increasing energy in the system the progressive non‐linearity leads to a hardening effect. One typical dynamical property of non‐linear systems is the frequency‐energy dependency of the resulting oscillations. A good graphic illustration is to plot such a dependency in a so called frequency‐energy plot (FEP). A NNM branch can be calculated by a numerical continuation method with starting at low energy level in a quasi linear regime and increasing the energy and reducing the period of the oscillation iteratively. Thereby a branch is a family of NNM oscillations with qualitatively equal motion properties [2]. In non‐linear systems internal resonances and other phenomena can occur. Several tongues can bifurcate from a NNM branch. Therefore ordinary continuation methods may fail at such bifurcation points. Here a predictor‐corrector‐method is used and different corrector algorithms are discussed for the branch continuation. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stabilization of the radial equilibrium of a tethered satellite with respect to out‐of‐plane initial perturbations
Authors: Steindl Alois 
Published: December 2014

AbstractWe investigate the stabilization of the radial equilibrium of a tethered satellite by tension control, if both in‐plane and out‐of‐plane deviations from the vertical position are taken into account. While in‐plane perturbations can be eliminated in finite time, the length rate change of the tether acts as parametric control on the out‐of‐plane deviations. Therefore the control becomes less effective, if the perturbation decreases.In order to improve the convergence we investigate the optimal control problem assuming no costs for the applied tension force but restricting the control force to a finite interval. For tether cconfigurations close to the vertical target position this approach yields a solution with singular control, which leads to a faster decay of the deviations. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter study of a multi‐body friction oscillator
Authors: de Payrebrune Kristin M. , Kröger Matthias 
Published: December 2014

AbstractIn many technical applications sliding contacts with multiple contact points or engagements exist, like between seals and rough surfaces, between grinding wheel and workpiece, or between granular material and storage box. In a simplified way these contacts can be represented by a friction oscillator with multiple bodies. The behavior of the friction oscillator with one body is already well known. However only few studies exist on the behavior of a friction oscillator with multiple bodies. In this study especially the dynamical behavior depending on the number of bodies, the friction characteristic and the velocity of the belt has been investigated. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conceptual Difficulties in Plasticity including the Gradient of one Scalar Plastic Field Variable
Authors: Wulfinghoff Stephan , Bayerschen Eric , Böhlke Thomas 
Published: December 2014

AbstractThis article discusses a conceptual problem of gradient plasticity theories including a scalar plastic field variable, the Laplacian of which enters the yield criterion. Since the plastic field variable is assumed a scalar, it contains no information on the direction of the plastic flow. The work at hand demonstrates that even arbitrarily small perturbations can determine the direction of the plastic deformation in many formulations, which is considered an unphysical behavior. In this sense, the solution is not stable with respect to the boundary conditions. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dual‐mixed finite element analysis of crystalline sub‐micron gold
Authors: Konchakova Natalia , Husser Edgar , Bargmann Swantje 
Published: December 2014

AbstractAn extended crystal plasticity model is applied to crystalline sub‐micron gold in order to study the mechanical response. Numerical results for different crystal sizes are presented and discussed. The governing equations are discretized and, subsequently, solved via a dual‐mixed finite element formulation [1, 2]. The evolution equation of the dislocation density is taken as a global field relation additionally to the balance of linear momentum, whereas the flow rule is solved locally at the Gauß point level [3,4]. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A general finite plasticity model with a smooth elastic‐plastic transition and isotropic hardening. A finite element formulation and numerical verification
Authors: Jabareen Mahmood 
Published: December 2014

AbstractA number of approaches for finite deformation elastoplasticity with different classes of kinematic decomposition have been published in the literature (e.g. additive split of the Lagrange strain, multiplicative split of the deformation gradient, additive split of the rate of deformation, etc.). In the present work, a general theoretical framework for modeling a smooth elastic inelastic transition for large deformations of rate independent elastic‐plastic and rate dependent elastic‐viscoplastic materials has been proposed. It is well known that in classical rate independent elastic‐plastic models the transition from the elastic regime to the plastic regime is rather sharp, while in the present model this transition is smooth and both rate independent and rate dependent models are characterized by overstress. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Macroscopic modeling of material interfaces based on atomistic descriptions
Authors: Sievers Christian , Clausmeyer Till , Mosler Jörn 
Published: December 2014

AbstractThe effective macroscopic properties of a broad variety of different materials are defined by the properties of the involved material interfaces. Grain boundaries in polycrystals represent a well‐known example. However, in contrast to classical bulk materials, the mechanical properties of material interfaces can oftentimes not be identified in a straightforward manner. In this paper, a multiscale framework is presented which allows to compute macroscopic properties of material interfaces based on molecular dynamics. The key idea of the elaborated multiscale framework is the coupling of an RVE associated with the atomistic scale to an RVE based on a continuum mechanics description by means of the principle of energy equivalence. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct evaluation of limit states of heterogeneous materials under cyclic thermo‐mechanical loadings
Authors: Chen Min , Hachemi Abdelkader , Markert Bernd 
Published: December 2014

AbstractClassical shakedown theorems and their extensions to various material models rest on the temperature‐independent coefficients. In this paper, the lower‐bound of direct methods is extended to the application on the heterogeneous materials with temperature dependent yield strength and elastic modulus. Moreover, a numerical platform is developed, which makes the practical application more convenient and efficient. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Failure in anisotropic nonwoven materials at finite deformation
Authors: Raina Arun , Linder Christian 
Published: December 2014

AbstractThe current work proposes a finite deformation strong discontinuity approach based modeling of failure in anisotropic materials with reorientation based micromechanical network model for the bulk response. These materials consist of randomly cross‐linked one dimensional filaments at their microstructure which undergo non‐affine deformation as well as reorientation upon loading before undergoing complete failure. The computationally efficient strong discontinuity approach allows to capture the failure kinematics by introducing a local problem where a strong discontinuity exists, thereby leading to an enhanced deformation gradient. A precise evaluation of the bulk response is done by homogenizing the physical microscopic response of constituent filaments where reorientation is introduced with an initial straightening effect of fiber undulations. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient Simulation of Short Fibre Reinforced Composites
Authors: Meyer Arnd , Springer Rolf 
Published: December 2014

AbstractLightweight structures become more and more important and one great class within these structures are parts produced by injection moulding. To improve the mechanical properties of these parts short fibers are injected within the molten plastics. Now a way to describe these properties without knowing the fibre orientation exactly is needed. We show an intuitive way, how mechanical properties of short fibre reinforced composites for linear thermoelasticity can be described and show the relation to other approaches. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the transformation equations for the shock and polynomial Equations of State in hydrocodes
Authors: Esteban Beatriz , Gebbeken Norbert 
Published: December 2014

AbstractThis paper compares two sets of equations that can be employed to transform the parameters of the shock Equation of State into those of the polynomial Equation of State used in hydrocodes. The first set is taken from literature, whilst the second set is derived by the authors, which can be seen as a correction to the first set of equations. Furthermore, the consequences on the numerical simulations of using the corrected set of equations is discussed. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical calculation of the tangent stiffness matrix in materials modeling
Authors: Meier Felix , Schwarz Cornelia , Werner Ewald 
Published: December 2014

AbstractThe Finite Element Method in the field of materials modeling is closely connected to the tangent stiffness matrix of the constitutive law. This so called Jacobian matrix is required at each time increment and describes the local material behavior. It assigns a stress increment to a strain increment and is of fundamental importance for the numerical determination of the equilibrium state. For increasingly sophisticated material models the tangent stiffness matrix can be derived analytically only with great effort, if at all. Numerical methods are therefore widely used for its calculation. We present our method to calculate the tangent stiffness matrix for the logarithmic strain measure. The approach is compared with other commonly used procedures. A significant increase in accuracy can be achieved with the proposed method. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter identification for rubber materials with artificial higher dimensional data
Authors: Mahnken Rolf , Nörenberg Nicole 
Published: December 2014

AbstractIn general, laboratory test render only a limited number of experimental data. Consequently, the prediction of material behaviour becomes a difficult task and, moreover, a statistical analysis with a statistically based approach is almost impossible. As a remedy to increase the number of data, artificial data are generated by stochastic simulation. As a consequence an arbitrary number of data is available and the process of parameter identification can be analysed statistically. Here, the special challenge is the consideration of spatial and inhomogeneous problems. In this work artificial data are generated for a elastomer strip with hole under tension. The inhomogeneous stress/strain fields are optically measured with an Aramis/GOM system and have to be fitted to a stochastic model in order to generate artificial data. B‐Splines are applied to fit the geometry of the test specimen and the measured data in space as well as in time. Parameter identifications applied and the resulting material parameters are statistically analysed. In the example, a statistical analysis of an Ogden model is performed. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐affine strain measures for continuum models of network materials
Authors: Ehret Alexander E. , Ogden Ray W. , Mazza Edoardo 
Published: December 2014

AbstractBased on stretch averaging, two non‐affine strain measures for materials with random network microstructure are suggested. The first concept provides a scaling between affine and non‐affine behaviour that is predefined by the network functionality. The second approach applies to fibres that experience strong reorientation upon macroscopic deformation of the network. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)