bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards Logical Framework for Sequential Design
Authors: Dzbor Martin , Zdrahal Zdenek 
Published: November 2020

Abstract
Engineering design is usually seen as a knowledge-intensive process that driven by certain objectives eventually delivers an artefact having the desired properties or functions. Design is inherently iterative and the design goals evolve together with the solutions. Many current design theories present more or less efficient ways for finding a suitable solution to the given goals. However, they often leave open the question of the ‘solution talkback’. Under ‘solution talkback’ we understand the reasoning process that is able to infer what formal amendments to the initial design specification need to be made in order to produce a feasible solution. Modified explicit design specification would in turn enable designers to refine the solutions to their design problems. This paper suggests an early-stage theory that incorporates some typical features of design problems, and defines a reasoning framework for the reflection on the actions in design. First, the key terms are defined that are elaborated later with the focus on generation of new design goals through the reflection on the partial design solutions.
Tolerance Optimization: A Decomposition Scheme, Variance Reduction and Fractional Approximation
Authors: Gadallah Mohamed H. 
Published: November 2020

Abstract
Development of involved optimization algorithms is not an easy task for several reasons: First, every analyst is interested in a specific problem; Second, the capabilities of these methods may not be fully understood a priori; Third, coding of multi-purpose and more involved algorithms is not an easy job.
In this paper, the optimization problem employing the near to global optimum algorithm is studied (Gadallah, M.H., 2000). The focus is to exploit 2 ideas: First, the algorithm can be modified to act as a variance reduction technique; Second, the algorithm can be modified to tackle the problem of system decomposition. Both ideas are novel within the context of statistical design of experiments. The first, if fully proved experimentally could yield the simultaneous integration of nominal and variance optimization possible. The second, can be extended to deal with multi-dimensional highly constrained systems with ease. These two ideas are explained wife the use of a simple example to illustrate the idea. An algorithm is developed that deal with the problem in several stages according to a predetermined decomposition scheme. The original objective and constraint functions are dealt with to suit each stage. Accordingly, all NP hard problems can ideally be transformed into NP complete ones with a consequence on the number of stages resulting from decomposition. Several decomposition scenarios are used and their results are compared numerically. Two orthogonal arrays and four composite arrays are used to plan experimentation; these are L27OA and L54OA and their subfamilies. These arrays are compared with respect to their statistical measures.
The algorithm as such, is very promising optimization tool, especially for coupling system decomposition and variance reduction. Past work focused on either decomposition or statistical optimization. This work offers both capabilities. Several studies are reviewed and conclusions are drawn.
Computation of Time-Varying Cross-Spectra by Harmonic Wavelets
Authors: Newland David E. 
Published: November 2020

Abstract
Harmonic wavelets provide an organised method for local computations of the cross-spectra between two signals. Each signal is analysed into its wavelet expansion. The product of the (complex) amplitudes of corresponding terms in each expansion is then a measure of the time varying cross-spectral density between the two signals. To ensure adequate discrimination at low frequencies, it is necessary introduce additional terms into the expansion by intentionally oversampling, but the principle remains unchanged and the method allows the amplitude and phase of time-varying cross-spectra to be identified at closely-spaced time intervals. Some examples illustrate the procedure, which can be programmed simply using an FFT algorithm.
Optimizing Parameters of a Two-Degree-of-Freedom Maglev System
Authors: Xu Zhixiang , Seto Kunisato , Tamura Hideyuki 
Published: November 2020

Abstract
Because a repulsive maglev vehicle only has extremely small uncontrollable damping force in its magnetically levitated gap, its vibration is a considerable problem. The one solution of this problem is to add a secondary suspension to the main system that is now practically used for Japanese type maglev train. In this paper, we first simplified the repulsive magnetic levitation vehicle with secondary suspension into a two-degree-of-freedom vibration model, and then analyzed the vibration properties of the system. Especially, we investigated the influence of the system parameters on the frequency responses of the system in detail, and found out that there are four fixed-points both in the frequency responses of car-body and truck. Similarly to the technique for dynamic absorber, but contrary to the aim of dynamic absorber with which to suppress the vibration of main mass, we successfully optimized the system parameters to suppress the car-body’s vibration that is equivalent to that of the additional mass of dynamic absorber by arranging the positions of the fixed-points.
A Relative Nodal Coordinate Formulation for Finite Element Nonlinear Analysis
Authors: Park J. H. , Choi J. H. , Bae D. S. 
Published: November 2020

Abstract
Nodal coordinates are referred to a fixed configuration in the conventional equations of equilibrium. Nodal coordinates are referred to the initial configuration in the total Lagrangian formulation and to the last calculated configuration in the updated Lagrangian formulation. This research proposes to use the relative nodal coordinates in representing the position and orientation for a node. Since the nodal coordinates are measured relative to its adjacent nodal reference frame, they are still small for a structure undergoing large deformations if the element sizes are small. As a consequence, many element formulations developed under small deformation assumptions are still valid for structures undergoing large deformations, which significantly simplifies the equations of equilibrium. A structural system is represented by a graph to systematically develop the governing equations of equilibrium for general systems. A node and an element are represented by a node and an edge in graph form, respectively. Closed loops are opened to form a tree topology by cutting edges. Two computational sequences are defined in a graph. One is the forward path sequence that is used to recover the Cartesian nodal deformations from relative nodal displacements and traverses a graph from the base node towards the terminal nodes. The other is the backward path sequence that is used to recover the nodal forces in the relative coordinate system from the known nodal forces in the absolute coordinate system and traverses from the terminal nodes towards the base node. One open loop and one closed loop structure undergoing large displacements are analyzed to demonstrate the efficiency and validity of the proposed method.
Dynamics of Rolling Wheel With Contact Rigidity and Slip
Authors: Terumichi Yoshiaki , Suda Yoshihiro , Sogabe Kiyoshi 
Published: November 2020

Abstract
In this paper, we discuss the dynamics of a rolling wheel with contact rigidity and slip. We propose the approach, using the distance between the center of the wheel and the contact point as an index to the elastic contact for this problem. We discussed about the generation and disappearance condition of slip with dynamic load and initial vertical displacement, using some results for simple cases. It is shown that contact rigidity influences on the time when slip generates or disappears and duration time of slip. It is also clarified that when the friction force reaches the tangent force after slip, slip does not always stop.
A New Plate Element Based on the Absolute Nodal Coordinate Formulation
Authors: Mikkola Aki M. , Shabana Ahmed A. 
Published: November 2020

Abstract
In this investigation, a method for the finite rotation and large deformation analysis of plates is presented. The method, which is based on the absolute nodal coordinate formulation, leads to a plate element capable of representing exact rigid body motion. In this method, continuity conditions on all the displacement gradients are imposed. Therefore, non-smoothness of the plate mid-surface at the nodal points is avoided. By developing such a plate element, a constant mass matrix is obtained, and as a consequence, the centrifugal and Coriolis forces are equal to zero. Generalization of the formulation to the case of shell elements is discussed. Numerical results are presented in order to demonstrate the use of the proposed method in the large rotation and deformation analysis of plates and shells.
Dynamics of Flexible Beam Using a Component Mode Synthesis Based Formulation
Authors: Kobayashi Nobuyuki , Sugiyama Hiroyuki , Watanabe Masahiro 
Published: November 2020

Abstract
This paper establishes a new formulation strategy for a flexible beam with large rotational motion. The finite element based formulation, which was previously developed for the analysis of the ‘Spaghetti Problem’ by the present authors, is extended to realize a low order and high accuracy beam model using a kind of component mode synthesis method. The deformation of the flexible beam is modeled by a combination of a static mode represented by a shape function and an analytically evaluated vibration mode clamed at both ends with respect to the body coordinate system. The body coordinate system satisfies the condition that the x-axis connects both ends of the beam. To demonstrate the efficiency and validity of the flexible beam model in multibody dynamics, a 2-link flexible robot arm is modeled as a flexible multibody system consisting of some rigid bodies and two flexible beams. Its validity is indicated by good agreement between numerical simulations and the experimental results.
Utilization of Coupled Simulation in the Fatigue Loads Prediction of a Hydraulically Driven Log Crane
Authors: Mikkola Aki M. 
Published: November 2020

Abstract
Welded structures, such as hydraulically driven booms, are disposed to fatigue damage. Design against fatigue requires information on the fatigue resistance of a structure’s critical details and the fatigue loads that act on each detail. The present paper introduces a method based on dynamic simulation for determining the fatigue loads in a hydraulically driven log crane. The detailed simulation model was built up in the MBS-software environment in which the flexible mechanism model and the equations describing the hydraulic system were combined. The complete simulation model was verified by comparing measurements to numerical results. This comparison shows that there is a clear correspondence between the simulated and measured results. It was thus shown that it is possible to create a simulation model which can be used realistically for determining stresses in fatigue analysis. The model was employed in the study of the fatigue loads, which are formed when the crane is being loaded.
Basin of Attraction of the Simplest Walking Model
Authors: Schwab A. L. , Wisse M. 
Published: November 2020

Abstract
Passive dynamic walking is an important development for walking robots, supplying natural, energy-efficient motions. In practice, the cyclic gait of passive dynamic prototypes appears to be stable, only for small disturbances. Therefore, in this paper we research the basin of attraction of the cyclic walking motion for the simplest walking model. Furthermore, we present a general method for deriving the equations of motion and impact equations for the analysis of multibody systems, as in walking models. Application of the cell mapping method shows the basin of attraction to be a small, thin area. It is shown that the basin of attraction is not directly related to the stability of the cyclic motion.
A Numerical Method for Multibody System Frictional Impact Simulation
Authors: Zakhariev Evtim V. 
Published: November 2020

Abstract
In the paper a numerical algorithm for modeling of impact of rigid and flexible multibody systems considering the nonlinear Coulomb friction is presented. The algorithm is developed on the basis of the kinematic decomposition of the contacting surfaces. The possible motion along the normal direction of the contact point tangential plane is considered generalized coordinate. The impulse-momentum equations are derived using a general algorithm for dynamics modeling and solved consequently for the two stages, compression and restitution, of the impact process. Rigid body impact theory and analysis of the contacting point relative velocity are applied for effective modeling of the events sliding-stiction and reverse sliding. The method presented considers either Newton’s or Poisson’s hypothesis for the coefficient of restitution. The same approach is used for flexible systems that are discretized using finite element theory. It is pointed out that, if rigid multibody systems are considered, the coefficient of restitution does not reveal the true picture of the impact process. Several examples are solved and compared with the results obtained in other treatments.
Analysis of Electromagnetic Excitation Sources of Noise and Vibration in Interior Permanent Magnet Motor
Authors: Ko Hong-Seok , Kim Kwang-Joon 
Published: November 2020

Abstract
The purpose of this paper is to characterize electromagnetic excitation forces in an IPM (Interior Permanent Magnet) motor and to analyze their effects on noise and vibration. To do this, the electromagnetic excitation forces are classified into three parts and contribution of each to the noise and vibration is investigated. The first is cogging torque; in order to overcome drawbacks of finite element method in the initial design stage, an analytical method is proposed. The second is electrical torque ripple due to current harmonics; a simple equation for characterizing the current harmonics with respect to the electrical torque ripple is developed. The third is the excitation force related to distribution of electromagnetic forces in air-gap; existence of this force is understood by finite element method.
The influence of the electromagnetic forces on the noise and vibration is investigated by doing modal analysis and operational deflection shape analysis.
Bayesian Updating of Nonlinear Model Predictions Using Markov Chain Monte Carlo Simulation
Authors: Beck James L. , Au S. K. , Yuen K.-V. 
Published: November 2020

Abstract
The usual practice in system identification is to use system data to identify one model from a set of possible models and then to use this model for predicting system behavior. In contrast, the present robust predictive approach rigorously combines the predictions of all the possible models, appropriately weighted by their updated probabilities based on the data. This Bayesian system identification approach is applied to update the robust reliability of a dynamical system based on its measured response time histories. A Markov chain simulation method based on the Metropolis-Hastings algorithm and an adaptive scheme is proposed to evaluate the robust reliability integrals. An example for updating the reliability of a Duffing oscillator is given to illustrate the proposed method.
Modeling Damping Effect due to High Transient Motion Using the Riemannian Space
Authors: Al Majid Ahmad , Dufour Régis 
Published: November 2020

Abstract
An original method for evaluating the dissipative effect in SDOF systems due to the transient phenomenon was presented in a previous article (Al Majid and Dufour, 2000). This method based on the use of an additional dimension, and the general relativity concept was validated experimentally. However, the function of the forcing frequency required to establish the metric of the space was identified using an experimental transfer function. In the present paper the main objective is to solve the geodesic equations in order to avoid the experimental identification of the function contained in the metric. The variational problem of the metric of Riemannian space gives three geodesic equations for the SDOF system studied. Solving these equations gives in particular the transient forced response which, when compared with experimental results, permits validating the proposed method and therefore proving that the transient motion bends the space-time.
Active Control of Wind-Induced Building Vibration Using a Linear Coupling Strategy
Authors: Hashemi S. Mohammad , Golnaraghi M. F. 
Published: November 2020

Abstract
The active control of building vibration is addressed. The aeroelastic lumped mass model of a building is designed to be used as the test bed for the active control system. The five story lumped parameter model was modeled as a cantilever beam exhibiting planar vibration. A Linear Coupling Control (LCC) strategy was implemented to eliminate the vibrations. An active (moving) mass damper (AMD) was first designed and experimentally implemented to control the first mode vibration of the system. An alternative pendulum control system was then designed and implemented. The proposed pendulum, having three times smaller mass than the AMD, was found to be more effective in reducing the building vibrations.
Dynamics of Towed Cables During Transient Motions
Authors: Ng Leslie , Rand Richard , Keith William 
Published: November 2020

Abstract
This work concerns the problem of determining the relative position of a towed cable when the towing vessel is moving in an arbitrary given fashion. In particular we are concerned with avoiding the tangling of individual towed cables when the towing vessel is towing multiple cables. A model is developed to describe the dynamics of the tow cables for arbitrary motions of the towing vessel. The model is then analyzed for constant speed circular motions of the towing vessel. A combination of analytic and numerical techniques are used in the analysis of the resulting differential equations.
A Refined Model for a Piezoelectric Transformer
Authors: Seemann Wolfgang E. , Gausmann Rainer 
Published: November 2020

Abstract
This paper is dedicated to Prof. Peter Hagedorn, Darmstadt University of Technology, Germany, on the occasion of his 60th birthday.
Usually piezoelectric actuators are nowadays simulated with the help of finite element codes. Analytical models are only used for very simple geometries like beams and plates or in those cases where piezoelectric patches are bonded to a beam or plate. Examples can be found in literature. However, it has to be kept in mind that there are still some problems for which standard finite element codes like ANSYS might get difficulties. One such problem is a piezoelectric transformer with an arbitrary load impedance connected to the electrodes of one of the piezoceramics. Such a system is investigated in this paper. To obtain results which are still valid if the diameter of the rod is not small compared to the wave length, a refined rod theory is used which takes into consideration also the inertia effects due to transverse contraction. To derive the equations of motion and the boundary conditions for such a system Hamilton’s principle for electromechanical systems is used. The equations of motion are solved and compared with experimental results. A comparison with results of a finite element analysis is also given for one special case which could be handled by ANSYS.
Investigation of the Dynamic Behavior of Railway Ballast Using Molecular Dynamics Simulations
Authors: Kruse Holger , Popp Karl 
Published: November 2020

Abstract
The molecular dynamics method (MD method) is a powerful tool for the investigation of granular materials like the railway ballast. The characteristics of this method are explained in detail. In contrast to a continuum description, each single stone of the ballast is taken into account. Since the ballast settlement is strongly influenced by the shape of the stones, in the two-dimensional model polygonal particles are used. These particles are surrounded by fixed boundary walls. At the top of the ballast particle layer, a single sleeper is positioned which is loaded by forces occurring at the real track. The contact forces are calculated from the overlap area of the particle geometries.
The paper includes information about the sensitivity of the model behavior on initial conditions and contact law parameters. Furthermore, the contact network, the quasi-static stiffness of the ballast layer and its long-term behavior are addressed. Particular emphasis is put on the description of current difficulties and challenges in applying the MD method.
Identification of a Micro-Slip Friction Damping Function Using Directed Genetic Programming
Authors: Gregory Julie J. , Paez Thomas L. , Coleman Ronald G. , Gregory Danny L. 
Published: November 2020

Abstract
This paper describes the application of directed genetic programming to explore the functional form of non-linear restoring forces that arise due to micro-slip friction. Data are obtained from an experiment to investigate the friction forces in a simple shear interface subjected to a vibration environment. A candidate functional form is proposed to model this friction, and a genetic search is then performed which seeks optimal parameters for the function. The resulting parameters provide the best fit of the proposed functional to the experimental data.
Large Deflection Dynamics and Control for Planar Continuum Robots
Authors: Gravagne Ian A. , Walker Ian D. , Rahn Christopher D. 
Published: November 2020

Abstract
This paper focuses on a class of robot manipulators termed “continuum” robots — robots that exhibit behavior similar to tentacles, trunks, and snakes. In previous work, we studied details of the mechanical design, kinematics, path-planning and small-deflection dynamics for continuum robots such as the Clemson “Tentacle Manipulator.” In this work, we discuss the dynamics of a planar continuum backbone section, incorporating a large-deflection dynamic model. Based on these dynamics, we formulate a vibration-damping setpoint controller, and include experimental results to illustrate the efficacy of the proposed controller.
Structural Diagnostics Using Nonlinear Analysis (SDNA) With Smart Sensor Arrays
Authors: Adams Douglas E. , Bono Richard W. 
Published: November 2020

Abstract
There are compelling needs to develop and install smart online monitoring and diagnostic tools for complex dynamic systems. Automated internal diagnostics and prognostics will help to extend service and design lives for new and aging aircraft, civil infrastructure, mission critical aerospace structures, automotive systems, and industrial machinery. The most innovative aspects of a proposed approach to smart structural diagnostics using nonlinear analysis (sDNA) are discussed here including the sensor array architecture and networked processing platform. A diagnostic technique using transmissibility functions is described for pinpointing the location and extent of damage. Since damage is spatial in nature, these transmissibility functions are well suited for analyzing either passive operating data or active forced response data. Strain gauges installed in sensor array packets are described as ideal for monitoring usage and characterizing damage while accommodating nonlinearity and uncertainty in the system and boundary conditions.