bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional finite elements for the analysis of soil contamination using a multiple‐porosity approach
Authors: El‐Zein Abbas , Carter John P. , W. Airey David 
Published: December 2005

AbstractA three‐dimensional finite‐element model of contaminant migration in fissured clays or contaminated sand which includes multiple sources of non‐equilibrium processes is proposed. The conceptual framework can accommodate a regular network of fissures in 1D, 2D or 3D and immobile solutions in the macro‐pores of aggregated topsoils, as well as non‐equilibrium sorption. A Galerkin weighted‐residual statement for the three‐dimensional form of the equations in the Laplace domain is formulated. Equations are discretized using linear and quadratic prism elements. The system of algebraic equations is solved in the Laplace domain and solution is inverted to the time domain numerically. The model is validated and its scope is illustrated through the analysis of three problems: a waste repository deeply buried in fissured clay, a storage tank leaking into sand and a sanitary landfill leaching into fissured clay over a sand aquifer. Copyright © 2005 John Wiley & Sons, Ltd.
On the Dynamics of Rolling Tires in Contact with Rough Road Surfaces
Authors: Brinkmeier Maik , Nackenhorst Udo 
Published: December 2005

AbstractFor the reduction of traffic noise significant progress has been achieved for the main engine of motor vehicles so far. Meanwhile the rolling noise of tires is the main source at speeds above 40 km/h for passenger cars and 60 km/h for trucks. So there is need for a simulation procedure of rolling tire dynamics and sound radiation [1].In a nonlinear steady state rolling analysis the deformation of the tire in contact with a plane road is computed. The next step is the eigenvalue analysis of the gyroscopic system yielding complex eigenvectors. The modal space of the tire system is excited by surface textures of the road in the contact region in a deterministic description. Modal superposition results in the dynamic response of the system in dependance of the excitation function. Additionally, the normal velocities of the tire surface are used as boundary conditions for the acoustic simulation of the sound pressure field. With these steps it is possible to determine and optimize the characteristics of tire structures with respect to lower noise levels for virtual prototyping. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Dynamics of Marine Systems in Random Waves
Authors: Ellermann Katrin 
Published: December 2005

AbstractThe dynamics of ships or offshore structures is influenced by several different effects, some of which have a distinctly nonlinear characteristic. Even though in many situations the motion can sufficiently be described by linear models, nonlinear phenomena play a crucial role in the investigation of some more critical operating conditions: Large amplitude motions, sudden jumps in the dynamical behavior and sensitivity to the initial conditions are likely to occur under some circumstances. The response of floating systems such as moored buoys and barges in regular waves can be approximated by analytical or numerical techniques. These analyses reveal the characteristics of different periodic motions. In order to determine how these responses change under a more general forcing, the motion of floating structures under the influence of random disturbances is described by probability distributions. Different mathematical tools can efficiently be applied to models with few degrees of freedom. The localized statistical linearization used here is also promising for larger systems. Modelling aspects of offshore structures and random waves are discussed as well as the determination of probability distributions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of the Forced Vibration of Two Bolted Half‐Pipes with Extended Friction Contacts
Authors: Genzo Alexander , Sextro Walter , Popp Karl 
Published: December 2005

AbstractThe present paper deals with the forced vibration analysis of a test structure. The test structure consists of two parts, an upper and a lower half pipe, joint in two bolted flanges which represent the extended friction contacts. Depending on the clamping loads different normal pressure distributions can be established in the contact interfaces. Since the test structure is loaded with a harmonic external force relative displacements occur in the contact interface. This leads to microslip effects affecting the dynamic behaviour. The experimental validation of the calculation method accounting for these effects is shown by comparing measured and calculated frequency response functions (FRF). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On low frequency disc‐brake vibrations
Authors: Hetzler H. , Seemann W. 
Published: December 2005

AbstractVibrations in vehicle disc‐brakes cause dissatisfaction of costumers and are therefore subject of intensive research activities. While initially the focus was primarily set on high‐frequency squeal noise, it has recently been shifted to more low and medium frequency noise, which is often referred to as groan, chirp oder judder. Within this article experimental results from our test installation are presented. Motivated by the study of these data and a thorough analysis of the functionality of the tested floating caliper disc‐brake, a 3‐DOF lumped parameter model is developed, which shows very good correspondence to the behavior observed in the experiments. Analysis of this model suggests a direct link between lateral disc‐stiffness and the groan frequency, while the circumferential stiffnesses of the pads and the support relate to moan or low frequency squeal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A numerical approach for a hemivariational inequality concerning the seismic interaction between adjacent buildings
Authors: Liolios Ast. , Karatasios G. , Liolios Ang. A. , Stavroulakis G. E. 
Published: December 2005

AbstractHighly nonlinear interaction effects arising in the seismic interaction between adjacent buildings can be modelled with hemivariational inequalities. This approach is outlined in the present paper. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inclusion of Manufacturing Induced Uncertainties into Linear Vibration of Structures
Authors: Machina Gangadhar , Zehn Manfred Werner 
Published: December 2005

AbstractOwing to manufacturing, composite materials and others can show considerable uncertainties in wall‐thickness, fluctuations in material properties and other parameters, which are spatially distributed over the structure. These uncertainties have a random character and they cannot be reduced by mesh refinement within the finite element (FE) model. So what we need is a suitable statistical approach to describe the parameter changing that holds for the statistics of the process and the correlation between the parameter spatially distributed over the structure. The paper presents a solution for a spatial correlated simulation of parameter distribution owing to the manufacturing process or other causes that is suitable to be included in the finite element analysis (FEA). The spatial variation of parameters is modelled using variogram approach and it has been applied into FEA. For example the effect of spatial variation of thickness and the effect of spatial variation of material properties has been studied in this part of work. The effect of thickness on buckling has been also studied. The results could be used to asses the robustness of the structure and to get limits for manufacturing induced uncertainties. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of Damping Performance of Tuned Mass Dampers and Shunted Piezo Elements
Authors: Neubauer Marcus , Oleskiewicz Robert , Popp† Karl 
Published: December 2005

AbstractIn technical applications, Tuned Mass Dampers (TMDs) are commonly used to reduce the vibrations of a system subjected to disturbance excitations. An alternative to TMDs are passive shunted piezo elements. Because of the ability to transfer mechanical energy into electrical energy and vice versa, an electromechanical vibration damper can be created by connecting a suitable passive resonance circuit. In this paper, criterions for optimal performance of both mechanical and electromechanical systems are derived, and maximum damping performances are compared. Further, a method to increase the damping performance of piezo elements by adding a negative capacitance is examined. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic Impedance Circuits in Semi‐Passive Vibration Control with Piezo‐Ceramics ‐ Efficiency and Limitations
Authors: Oleskiewicz Robert , Neubauer Marcus , Krzyzynski Tomasz , Popp† Karl 
Published: December 2005

AbstractElectrical circuits that represent complex impedance connected to the plates of piezo element affect the frequency response function of compound electromechanical systems. The external network consisting of inductance results in absorbing a certain frequency of vibrations. The performance can significantly be increased using negative capacitance. All the negative impedance elements are achievable via semi‐passive way with the use of an electronic gyrator realized by operational amplifiers that require power supply. Its performance is limited due to the maximum voltage operational amplifiers can produce. The higher excitation forces require higher output voltages of amplifiers. The aim of the paper is to present the relation between the required voltage on synthetic impedance and force excitation in 1DOF vibrating system regarding parameters of piezo element and mechanical system for absorbing case. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the dynamics of circulating monocable aerial ropeways
Authors: Renezeder Hans C. , Steindl Alois , Troger Hans 
Published: December 2005

AbstractWe investigate the dynamics of a hauling rope modelled as an inextensible completely flexible string and calculate the first natural frequencies. Furthermore we discuss the sensitivity of the model on the operating speed of the ropeway. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of Nonlinear Contact Elements
Authors: Schmidt‐Fellner A. , Bruns J.‐U. , Popp K. 
Published: December 2005

AbstractFriction damping is widely used to reduce vibration amplitudes and the resulting dynamic stresses. Before experimental tests of a new friction damper can be conducted, numerical simulations are carried out to evaluate the damping performance. Many systems with friction contacts can be divided into the linear parts of the structure and a nonlinear contact model. Therefore the simulation model usually comprises a modal description of the linear structures, a rigid body model of the friction dampers and contacts with elasticity and friction [1].In this paper an identification procedure is presented that allows the determination of contact parameters from measured frequency response functions. The procedure involves calculation of the model's frequency response by the Harmonic Balance Method (HBM) and the Method of the Harmonic Balance with Higher Harmonics (HHBM). The identification results are gained from measurements at a pair of blades coupled either by shrouds [2] or by underplattform dampers [1]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact Analysis using Modal Reduction
Authors: Seifried Robert , Eberhard Peter 
Published: December 2005

AbstractIn impact analysis, high frequency wave phenomena and plastic deformation are important effects. For numerical impact analysis including these effects, different models are presented based on modally reduced linear finite element models and nonlinear finite elements. The numerical results are verified by experimental investigations using Laser‐Doppler‐Vibrometers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Vibrational Behavior of Bladed Disks in Consideration of Friction Damping and Contact Elasticity
Authors: Siewert Christian , Panning Lars , Popp† Karl 
Published: December 2005

AbstractRotating turbine blading is subjected to fluctuating gas forces during operation that cause blade vibrations. One of the main tasks in the design of turbomachinery blading is the reduction of the vibration amplitudes of the blades to avoid high resonance stresses that could damage the blading. The vibration amplitudes of the blades can be reduced significantly to a reasonable amount by means of friction damping devices such as underplatform dampers. In the case of blade vibrations, relative displacements between the friction damping devices and the neighboring blades occur and friction forces are generated that provide additional damping to the structure due to the dry friction energy dissipation. In real turbomachinery applications, spatial blade vibrations caused by a complex blade geometry and distributed excitation forces acting on the airfoil accur. Therefore, a three dimensional model including an appropriate spatial contact model to predict the generalized contact forces is necessary to describe the vibrational behavior of the blading with sufficient accuracy, see [1] and [2]. In this paper the contact model presented in [2] is extended to include also local deformations in the contacts between underplatform dampers and the contact surfaces of the adjacent blades. The additional elasticity in the contact influences the resonance frequency of the coupled bladed disk assembly. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second‐Order Differential Equations Exhibiting Spectral Gaps
Authors: Wagner N. , Gaul L. 
Published: December 2005

AbstractWe consider the numerical solution of a linear second‐order differential equation, which is an underlying equation in many engineering applications. The response of such a system is typically dominated by a relatively small number of the lowfrequency modes. Using projections on certain eigenspaces or generalized eigenspaces of the system matrix that are induced by the matrix sign function, it is shown that the original problem may be reduced to a smaller subproblem that may be handled with significantly less computational work. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minimalkoordinatendarstellung bei gyroskopischen Systemen mit einseitigen Bindungen
Authors: Waltersberger Bernd , Wauer Jörg 
Published: December 2005

AbstractSysteme mit einseitigen Bindungen stellen bei gyroskopischen Systemen einen wichtigen Sonderfall dar, wie er z.B. bei durch Delamination geschädigten Rotoren aber auch bei auf einseitigen Stützen gelagerten durchströmten Rohren auftritt. Speziell bei gyroskopischen Systemen ist bereits das Auffinden einer stationären Lösung aufgrund zentrifugaler Effekte erschwert. Das Problem der stationären Lösung wird als Lineares Komplementaritätsproblem (LCP) formuliert, dessen Lösung Ausgangspunkt einer Minimalkoordinatendarstellung der Bewegungsgleichung ist. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibration suppression of self‐excited oscillations by parametric inertia excitation
Authors: Dohnal Fadi 
Published: December 2005

AbstractThe main objective of this contribution is to show the phenomenon of full vibration suppression of a simple two degrees of freedom rotary oscillator by interaction between self‐excitation and parametric excitation. One disk is under the influence of self‐excitation, modelled by a negative damping coefficient, while the moment of inertia of the second disk is periodically varied in time within an open‐loop control with a fixed frequency. Both disks are coupled by a linear spring‐element. Parametric excitation develops equations of motion with time‐periodic coefficients. Using the averaging method for a firstorder approximation general conditions for full vibration suppression are analytically derived for the two degrees of freedom system with harmonic inertia variation. The approximated analytical stability predictions are verified and compared to results obtained from numerical time integration of the original equations of motion. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constructing Robust Feedback Laws by Set Oriented Numerical Methods
Authors: Grüne Lars , Junge Oliver 
Published: December 2005

AbstractIn [8, 6] a numerical method for the construction of optimally stabilizing feedback laws was proposed. The method is based on a set oriented discretization of phase space in combination with graph theoretic algorithms for the computation of shortest paths in directed weighted graphs. The resulting approximate optimal value function is piecewise constant, yielding an approximate optimal feedback which might not be robust with respect to perturbations of the system. In this contribution we extend the approach to the case of perturbed control systems. Based on the concept of a multivalued game we show how to derive a directed weighted hypergraph from the original system and generalize the corresponding shortest path algorithm. The resulting optimal value function yields a robustly stabilizing approximate optimal feedback law. This note is an abbreviated version of [5]. For the proofs of the statements here we refer to the full paper. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Modeling and Tracking Control of a Hydraulic Rotary Vane Actuator
Authors: Heidtmann Frank , Bröcker Markus 
Published: December 2005

AbstractRotary vane actuators as rotational drives provide rotational movements directly because they are constructed as a joint and actuator in one. So it is possible to pass on the disadvantageous transmission kinematics used with the so far usual differential cylinders at the arms of large manipulators. However, the use of hydraulic rotary vane actuators is associated with high internal oil leakage and/or high friction. Therefore, a nonlinear dynamic model for such an actuator, driving a rigid robot arm, as well as its nonlinear control are derived. To achieve tracking control a model based control law is set up using fundamental linear differential equations for the tracking error. The control law is implemented and tested on a testbed, the produced experimental results are presented. The same control algorithm can also be used to realize nonlinear disturbance attenuation for hydraulic rotary vane actuators via tracking control. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Combination of Flatness‐Based Tracking Control with Passivity‐Based Control for a Certain Class of Infinite‐Dimensional Systems
Authors: Kugi Andreas , Daniel Daniel 
Published: December 2005

AbstractThis contribution is devoted to the infinite‐dimensional control design for a certain class of infinite‐dimensional systems. As first example a piezoelectric cantilever with a tip mass is considered. The control objective is to provide two independently controllable degrees‐of‐freedom for the tip mass in form of the tip position and the tip angle. The control concept being proposed consists of an open‐loop flatness‐based tracking controller and a linear dynamic feedback controller in order to asymptotically stabilize the closed‐loop error system. A similar concept is then applied to a second example, a gantry crane system with heavy chains and a payload. Thereby, the knowledge of the energy flows into and within the system is exploited to derive a stabilizing controller of the error system by means of the integrator backstepping method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Causal polynomial stabilization of forward models for discrete systems
Authors: Lampe Bernhard P. , Rosenwasser Efim N. 
Published: December 2005

AbstractThe paper provides the set of all stabilizing causal controllers in a parameterized form for the forward model of any strictly causal discrete‐time MIMO LTI model. As an example the causal stabilization of the double integrator is considered. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Control of nonlinear systems in singular problems
Authors: Popescu Mihai 
Published: December 2005

AbstractThe minimum singular functional control problem is analyzed for a class of multi‐input affine nonlinear systems. We develop an algorithm for solving the singular problem that is applicable whether or not singular sub‐arcs exist in the optimal control. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some Remarks on Distributed PCHD‐Systems
Authors: Schlacher Kurt , Ennsbrunner Helmut 
Published: December 2005

AbstractPort controlled Hamiltonian systems with dissipation are a well known tool for the modeling and the controller design for plants, described by nonlinear ordinary differential equations. This contribution presents a possible extension to systems, described by partial differential equations, where the state manifold and the input space of the ODE case are replaced by new geometric structures. This approach takes dissipative effects into account and shows, how distributed ports can be introduced. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Tracking Controller for a Certain Class of Nonlinear Systems
Authors: Stadlmayr Richard , Schlacher Kurt 
Published: December 2005

AbstractController design methods based on flatness and passivity are well established. These methods are applied to PCHD systems such that flatness is used to achieve a high tracking performance and passivity ensures disturbance rejection and robustness. Since the error system, written in displacement coordinates, is not a PCHD system in general, we present conditions, which ensures this property. Therefore, one can apply methods from passivity control to stabilize the error dynamics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity analysis of discontinuous parametric periodic systems
Authors: Wójcicki Zbigniew , Śniady Paweł 
Published: December 2005

AbstractThe paper concerns the complex eigensolutions sensitivity analysis of parametric periodic system. The derivatives of (so called) monodromy matrix (Floquet transient matrix) were the first calculated. Then the first derivatives of multiplicators, which are the complex eigenvalues of monodromy matrix, were obtained. The theory has been expanded to cover a class of discontinuous parametric periodic excitation. Furthermore, the method was generalized, so that the system parameters, on which the parametric excitation period depends, can now be a design parameter. In particular, it has become possible to use the parametric excitation period as a design parameter. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity Analysis of Human Leg Metabolical Costs
Authors: Ackermann Marko , Schiehlen Werner 
Published: December 2005

AbstractThe human walking is characterized by skeletal dynamics and muscle excitation patterns minimizing the metabolical energy. This criterion is applied to assess the performance of lower limb prosthetic devices, and to evaluate therapies for patients presenting gait disorders. It is desirable, therefore, to dispose models of the human normal and pathological gaits capable of estimating the metabolical energy expenditure.For the swing phase of normal and pathological gaits a musculoskeletal model of the lower limb is presented to estimate metabolical energy expenditure. The mechanical model has three degrees of freedom and is actuated by eight Hill‐type muscle units, and the model for the metabolical costs is adopted from literature. In this paper a combination of inverse and direct dynamics is used, and a sensitivity analysis of the dynamical behavior and the corresponding metabolical costs estimations with respect to parametrized neural excitations is performed. The leg motions are based on experiments in a gait analysis laboratory. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimierung der Kontaktgeometrie einer Ringplattform
Authors: Bestle Dieter 
Published: December 2005

AbstractNeuere Verfahren der Schornsteinbeseitigung in Kraftwerken verwenden Plattformen mit vorgespannten Ringseilen und kraftschlüssigem Kontakt. Die geometrische Auslegung der angepressten Pratzen und der Ringseilform lässt sich als Mehrkriterien‐ bzw. Min‐Max‐Optimierungsproblem formulieren und lösen. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)