bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Reproducible Excitation Mechanism for Analyzing Electric Guitars
Authors: Hanss Michael , Bestle Pascal , Eberhard Peter 
Published: October 2015

AbstractThis contribution presents the excitation mechanism of an experimental set‐up for measuring the structural behavior of an electric guitar body using Laser‐Doppler‐Vibrometers, to be compared to the generated sound. It is the aim of this investigation to gain insight into the influence on the sound of materials and designs of the large variety of commercially available electric guitars. The core of the experimental set‐up is the excitation mechanism, which has been developed to guarantee a well‐defined and absolute reproducible excitation of the guitar string in order to detect even small differences in sound. This mechanism has been constructed making use of the methods of multibody dynamics and optimization. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transient amplification of maximum vibration amplitudes
Authors: Bonhage Marius , Hentschel Olaf Peter , Panning‐v. Scheidt Lars , Wallaschek Jörg 
Published: October 2015

AbstractMany low damped structures as turbine blades or drill strings are exposed to high dynamical loads causing high vibration amplitudes. These applications comprise sub‐critical eigenfrequencies. Hereby, the lower eigenfrequencies have to be passed before reaching the operating point. Most investigations of vibration amplitudes caused by a resonance passage deal with the computation of single degree of freedom systems. Thereby, it has been shown that the stationary vibration response provides the highest possible amplitude. Further it can be stated that the maximum vibration response of the resonance passage decreases with an increasing sweep velocity [3]. Isolated modes of linear systems can be represented by single degree of freedom systems. Subsequently a mode shape can be described by the multiplication of the amplification function of the mode and the belonging eigenvector. There are only some recent works that deal with resonance passages of vicinal modes, e. g. [1].In this paper the resonance passage of a three dimensional system with nearby modes is studied. To calculate the transient vibration response an analytical approach is used. It is shown that the maximum amplitude of the stationary vibration response is not the upper limit for the maximum amplitude of the resonance passage. Thus, the maximum amplitude may rise while the sweep velocity increases. Hence, regarding a multi degree of freedom system the maximum amplitude of the resonance passage can exceed the maximum amplitude of the stationary vibration response. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active damping control for an underactuated multibody system
Authors: Burkhardt Markus , Morlock Merlin , Seifried Robert , Eberhard Peter 
Published: October 2015

AbstractLight‐weight robots and manipulators stand out due to their very good weight‐to‐load ratio and a low energy consumption. Unfortunately, the light‐weight design yields a lower stiffness, which results in undesired elastic deformations, especially during high‐speed working motion. One way to limit these unwanted oscillations can be implemented with modifications of the command signals, e.g. by input shaping or pre‐computed feed‐forward control. However, a feedback control‐concept has the ability to provide a fast compensation of elastic deformations due to high‐speed working motions or in case of unwanted environment contact as well as in the presence of other external disturbances. In this contribution, an active damping control (ADC) for fast moving manipulators with significant structural elasticities is presented. This approach does not require additional actuators and it is suitable for a large variety of manipulators that exhibit structural vibrations. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coupling Elastic Bodies with an Enhanced Craig‐Bampton‐like Scheme
Authors: Eberhard Peter , Holzwarth Philip 
Published: October 2015

AbstractElastic multibody systems are widely used as description of mechanical systems that consist of separable components. These components are represented by elastic bodies that interact by the means of force and damping elements as well as boundary conditions. The description of the elasticity is usually provided by a linear finite‐element model. If the bodies are densely meshed, a large system of differential equations is obtained. The numerical effort can be reduced by model order reduction. This contribution presents reduction approaches that are especially well suited for the elastic multibody system framework. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational Integrators for Thermo‐Viscoelastic Discrete Systems
Authors: Kern Dominik , Romero Ignacio , Groß Michael 
Published: October 2015

AbstractVariational integrators are modern time‐integration schemes based on a discretization of the underlying variational principle. In this paper, Hamilton's principle is approximated by an action sum, whose vanishing variation results in discrete Euler‐Lagrange equations or, equivalently, in discrete evolution equations for the position and momentum. In order to include the viscous and thermal virtual work (mechanical and thermal virtual dissipation), Hamilton's principle is extended by D'Alembert terms, which account for the time evolution equation of the internal variable and Fourier's law.From this variational formulation, variational integrators using different orders of approximation of the state variables as well as of the quadrature of the action integral are constructed and compared. A thermo‐viscoelastic double pendulum comprised of two discrete masses connected by generalized Maxwell elements, and subject to heat conduction between them serves as a discrete model problem. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Projection formulation of the cavitation problem in elastohydrodynamic lubrication contact
Authors: Krinner Andreas , Schindler Thorsten , Rixen Daniel 
Published: October 2015

AbstractThis contribution presents an alternative numerical method on how to find the cavitation region in elastohydrodynamic (EHD) lubrication using an augmented Lagrangian approach. A theoretical framework for the use of a projection formulation instead of a Linear Complementarity Problem (LCP) is given and the application to multibody systems with EHD contacts is shown. With this new formulation the cavitation condition can be covered by an additional algebraic equation. The projection formulation is applied to the steady‐state as well as to the dynamic, mass conservative treatment of the cavitation problem. A numerical verification is given for a rigid rotor with unbalance in an elastic bearing. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonexpansivity of the Newton's Cradle Impact Law
Authors: Leine Remco I. , Winandy Tom 
Published: October 2015

AbstractThe 3‐ball Newton's cradle is used as a stepping stone to divulge the structure of impact laws. A continuous cone‐wise linear impact law which maps the pre‐impact contact velocities to the post‐impact contact velocities is proposed for the 3‐ball Newton's cradle. The proposed impact law is kinematically, kinetically, and energetically consistent. It reproduces all the classical experimental outcomes. Moreover, the impact law has the mathematical property of being non‐expansive. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Back‐Transformation into Physical Configuration Space after Model Order Reduction onto a General Subspace
Authors: Lein Claudius , Beitelschmidt Michael 
Published: October 2015

AbstractModel order reduction (MOR) techniques that project onto a general subspace are common practice. In Elastic Multi‐Body‐Dynamics (EMBD) distinct interface coordinates are required for the interconnection of the elastic structure and the multi‐body system. For that reason, a physical interpretation of the coordinates is mandatory, which is not the case for reduced order models in a general subspace. To make alternative MOR techniques accessible for EMBD, a back‐projection approach was introduced by [1]. Therein, the system is projected back onto the physical configuration space, which requires the inversion of the master partition of the projection matrix. But the procedure lacks of robustness and generality. A novel approach is introduced by generating additional master coordinates using sensor placement methods, e.g. the Effective‐Independence‐algorithm (EfI) [2]. By using a rank criterion for the automatic selection of additional coordinates, the improved back‐transformation performs properly and without damaging the reduced order model at a fairly small computational overhead, which is demonstrated at the example of a gear box housing. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Error estimation approach for controlling the comunication step size for semi‐implicit co‐simulation methods
Authors: Meyer Tobias , Schweizer Bernhard 
Published: October 2015

AbstractIn this paper, an approach for controlling the macro‐step size in connection with co‐simulation methods [1, 2, 4] is suggested. The investigated step‐size controller is tailored for semi‐implicit co‐simulation techniques. Concretely, we consider predictor/corrector co‐simulation approaches [3]. By comparing variables from the predictor and the corrector step, an error estimator for the local error can be constructed. Making use of the estimated local error, a step‐size controller for the macro step‐size can be implemented. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An explicit approach for time‐optimal trajectory planning for kinematically redundant serial robots
Authors: Reiter Alexander , Springer Klemens , Gattringer Hubert , Müller Andreas 
Published: October 2015

AbstractKinematically redundant serial robots have become industrially important due their increased workspace and their inherent capability of null space motion resulting in remarkable adaptiveness to specific tasks compared to conventional, non‐redundant manipulators. Attempting to increase the cost‐effectiveness of industrial processes, introducing minimum‐time trajectories may yield economical advantages due to reduced motion cycle times. This contribution presents a method that uses joint space decomposition and analytic inverse kinematics as well as standard optimization techniques to obtain minimum‐time B‐spline joint trajectories along prescribed task space paths for kinematically redundant serial robots. It is shown that the present method was successfully applied to a planar manipulator. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Guideway based damping control of vehicle suspensions
Authors: Schiehlen Werner 
Published: October 2015

AbstractThe information on the routing of a road provided by a navigation system can be used by the driver of a vehicle with adaptive shock absorber to decide either for optimal comfort or optimal safety depending on the course of the guideway. However, the assessment criteria comfort and safety are with respect to the shock absorber in conflict with each other. In particular, maximal safety on a curvaceous road results in lower comfort. Thus, deciding on high safety means low comfort conveying a warning to the driver to reduce the speed. The methods applied in this paper originate from multibody dynamics, and they are extended by the stochastic road unevenness and the guideway curvature available to the driver from a navigation system using GPS data. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards effective mechanical properties of skeletal muscle tissue via homogenisation
Authors: Bleiler Christian , Ponte Castañeda Pedro , Röhrle Oliver 
Published: October 2015

AbstractThe constitutive modelling of skeletal muscle tissue in a continuum‐mechanical framework demands the consideration of many complex material characteristics. This complexity stems from the microscopic arrangement of different structural elements, such as, for example, sarcomeres and connective tissue. The former are responsible for the active contractile behaviour while the latter are mainly responsible for the passive stiffness of the muscle tissue. Thus, it is highly challenging to build appropriate macroscopic models based on phenomenological descriptions and yet cover most of the complex material behaviour. Strain‐energy functions have to be adapted for every significant material phenomena coming from experimental testing of muscle tissue. Another way to treat the modelling of active muscle tissue is to describe important parts of the heterogeneous microstructure and use homogenisation approaches to derive effective overall properties. This contribution aims to investigate and develop new homogenisation techniques for passive skeletal muscle tissue and is the first step towards the ultimate goal of developing a consistent framework that allows to derive macroscopic material properties for active muscle tissue based on microstructural characteristics. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A geometric approach to characterize rigidity in proteins
Authors: Budday Dominik , Leyendecker Sigrid , van den Bedem Henry 
Published: October 2015

AbstractKinematic analysis, in contrast to sophisticated molecular dynamics simulations, can provide high‐level insights into conformational diversity of proteins and other biomolecules, with broad implications for human health. Here, we model a protein as a kinematic linkage and present a new geometric method to characterize molecular rigidity. While existing combinatorial constraint counting is limited to generic structures, our geometric approach is also valid for non‐generic linkages. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Calculation of Fiber Orientation in Three‐Dimensional Arterial Walls
Authors: Fausten Simon , Balzani Daniel , Schröder Jörg 
Published: October 2015

AbstractIn this contribution an approach for the fiber reorientation in three‐dimensional arterial walls is presented. In detail the load‐bearing capacity of the tissue is increased by re orienting the fibers with respect to the principal stresses, cf. [1]. The improved fiber reorientation algorithm is combined with the polyconvex nonlinear anisotropic material model presented in [3]. The results of a three‐dimensional finite element simulation, where the reorientation approach is applied to a short segment of a patient‐specific arterial geometry, are presented. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A multi‐scale time‐dependent constitutive model of soft collagenous tissue
Authors: Hillgärtner Markus , Linka Kevin , Itskov Mikhail 
Published: October 2015

AbstractThis contribution presents a micro‐mechanically motivated, time‐dependent constitutive model of soft biological tissues. It considers seperate contributions of the matrix material, collagen fibrils, proteoglycans (PGs) as well as their interactions. It is based on the observations [6], that PG bridges facilitate sliding between fibrils.The initial overlapping lengths of the PG bridges are statistically distributed and decrease due to slippage. A linear‐elastic force response of a PG bridge is assumed. Damage of the PG bridges is reversible and decays over time (cf. Gupta et al. [1]). This behaviour is taken into account by a healing model based on the evolution of the overlapping length.The damage of the PG bridges decreases the PG density and in turn increases the fibril contact, leading to fibril stretch. The strain energy function of fibrils is based on the response of single tropocollagen molecules and takes both, an entropic and an energetic regime into account. At higher strains, fibrils can additionally undergo damage, which in contrast to the PG damage is irreversible.The so obtained constitutive model is capable to predict several mechanical phenomena of soft tissues, such as non‐linearity, Mullins effect, hysteresis and permanent set. Finally the model is compared against experimental data available in the literature. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of skin anisotropy directions for identifying stress free reference configuration of the female breast
Authors: Li Xuhui , Jabareen Mahmood , Raith Stefan , Itskov Mikhail 
Published: October 2015

AbstractBiomechanical simulations of the female breast are important for surgical applications such as implants augmentation, tumorectomy and reconstruction after the tumor removal. One of the main challenges for such breast simulations is to define its reference configuration which can be considered as a stress free state. Indeed, MRI (Magnetic Resonance Imaging) scans of the breast can be obtained only under gravitational load which introduces a considerable stress and strains level for any position of the patient. Moreover, realistic material properties especially anisotropy of skin should be taken into account. This anisotropy can play an important role but has not so far been considered in biomechanical simulations of the breast. In the current contribution, we implement an iterative method to define the reference configuration of the breast model according to MRI data of certain individuals in the prone position by taking into account the anisotropy directions of skin. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of microvascular tortuosity in tumor transport phenomena and future perspective for drug delivery
Authors: Penta Raimondo , Ambrosi Davide 
Published: October 2015

AbstractWe tackle the fluid transport problem in vascularized tumors by solving a double Darcy model obtained via multiscale homogenization. The hydraulic conductivities of the capillary and interstitial compartments are computed solving classical problems on the representative periodic cell, which encodes details of the microvasculature. Microvascular tortuosity leads to a dramatic decrease of the capillary hydraulic conductivity, and the corresponding lowering in the pressure drop impairs tumor blood flow and consequently advection of molecules. Further perspectives for anti‐cancer agents delivery are illustrated. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An algorithmic strategy for the simulation of bone healing directly on computed tomography data
Authors: Roland Michael , Tjardes Thorsten , Dahmen Tim , Otchwemah Robin , Slusallek Philipp , Bouillon Bertil , Diebels Stefan 
Published: October 2015

AbstractAn algorithmic strategy for the modelling and simulation of bone healing is presented. The algorithm works directly on the computed tomography data and simulates, after an appropriate volume meshing, a mechainically driven healing concept which is based on competitive and dynamical mechanical parameters. The finite element simulations are done with realistic boundary conditions from patient‐specific OpenSim simulations. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mechanics of growing tumors: impact of modeling assumptions and boundary conditions on reliability of numerical results
Authors: Sciumè Giuseppe , Schrefler Bernhard A. , Santagiuliana Raffaella , Zavarise Giorgio 
Published: October 2015

AbstractA recent computational model for tumor growth is presented. The mathematical model, based on thermodynamically constrained averaging theory (TCAT), is shortly summarized in the first part; then the attention is focused on modeling hypothesis and their impact on numerical results. Perspectives for future developments of the presented multiphase model are outlined at the end of the paper. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of Mechanical Properties in Tissues Undergoing Deformation‐Related Fiber Remodeling Processes
Authors: Topol Heiko , Demirkoparan Hasan 
Published: October 2015

AbstractWe consider a biological fibrous soft tissue in which fibers are distributed in all directions. The mechanical properties of the fibers evolve due to a continuous remodeling process. The model to describe these fiber properties is based on the strain energy density of the protofibers and a survival kernel which describes the deformation‐related property changes. In particular, this study investigates the development of the fiber orientation density for different choices of the fiber creation rate and fiber dissolution rate models. It has been shown that the fiber orientation density depends on both the history of the deformation and the deformation state of the fibers at the time of their creation. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of Residual Stress Distributions and Opening Angles of 3D Patient‐Specific Arterial Walls
Authors: von Hoegen Markus , Schröder Jörg 
Published: October 2015

AbstractA method to incorporate residual stresses in arteries, based on the assumption of smooth transmural stress measure distributions with slight slopes, is discussed. The artery is first loaded with the internal blood pressure without considering any residual stresses. With help of suitable stress invariants and volume averaged mean values on specific sectors domains, the stress gradient is iteratively decreased in radial direction. In order to assess the accuracy of the method, a three‐dimensional patient‐specific arterial geometry, suffering from atherosclerosis, is considered. These was reconstructed from ultrasound based medical imaging, see [2]. Moreover, the radially sliced arteries can be loaded exclusively with the calculated residual stresses in order to predict the opening angle. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermo‐mechanical modeling of crack propagation in dynamically loaded elastomer specimens using a scaled boundary finite element approach
Authors: Behnke Ronny , Kaliske Michael 
Published: October 2015

AbstractRecently, a scaled boundary finite element (SBFE) formulation for geometrically and physically nonlinear materials has been developed using the scaled boundary finite element method (SBFEM). The SBFE formulation has been employed to describe plane stress problems of notched and unnotched hyperelastic elastomer specimens. In this contribution, the derived SBFE formulation is extended to nonlinear time‐ and temperature‐dependent material behavior. Subsequently, the SBFE formulation is incorporated into a crack propagation scheme to model crack propagation in cyclically loaded elastomer specimens of the so‐called tear fatigue analyzer (TFA). (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of an elastoplastic material model coupled to nonlocal damage in an implicit‐gradient framework
Authors: Brepols Tim , Wulfinghoff Stephan , Reese Stefanie 
Published: October 2015

AbstractIn this work, an elastoplastic material model coupled to nonlocal damage is discussed which is based on an implicit gradient‐enhanced approach. Combined nonlinear isotropic and kinematic hardening as well as continuum damage of Lemaitre‐type are considered. The model is a direct nonlocal extension of a corresponding local model which was presented earlier (see e. g. [1], [2], [3]). Conclusions drawn from a numerical benchmark test performed in this study demonstrate that the nonlocal damage model is suitable to provide mesh‐independent solutions in finite element simulations. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Model reduction and clustering techniques for crash simulations
Authors: Fehr Jörg , Grunert Dennis 
Published: October 2015

AbstractModel reduction in car crash simulations is a fairly new research field. In this paper, a possible workflow is presented: Since nonlinear behavior can occur, parts with linear and nonlinear behavior need to be separated with clustering methods such as k‐means or spectral clustering. For the latter, a nonlinear reduction technique such as POD‐DEIM needs to be applied. A longitudinal chassis beam of a 2001 Ford Taurus is used to examine the different clustering methods. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)