Initial-value ordinary differential equation solution via variable order Adams method (SIVA/DIVA) package is collection of subroutines for solution of nonstiff ordinary differential equations. There are versions for single-precision and double-precision arithmetic. Requires fewer evaluations of derivatives than other variable-order Adams predictor/ corrector methods. Option for direct integration of second-order equations makes integration of trajectory problems significantly more efficient. Written in FORTRAN 77.

Solving Ordinary Differential Equations

Kinematic analysis of mechanisms kinematic synthesis of mechanisms simple mechanisms and coupler curves cams spur gears helical, spiral, worm and bevel gears gear trains hydrodynamic lubrication static force analysis inertia force analysis combined static and inertia force analysis turning moment diagram and flywheel balancing of rotating components balancing of reciprocating components gear forces.

Mechanism and machine theory

Ing. Holger Steeb, Dr.-Ing. Fehmi Cirak, Prof. Dr.-Ing. Ekkehard Ramm, University of Stuttgart, Department of Civil Engineering, Institute of Structural ...

Zeitschrift für angewandte mathematik und mechanik

http://heraclitus.uth.gr/main/sites/default/files/phd_public_uploads/1-s2.0-S0045794912002520-main.pdf

Component mode synthesis techniques for finite element model updating

Polynomial chaos representations for non-Gaussian random variables and stochastic processes are infinite series of Hermite polynomials of standard Gaussian random variables with deterministic coefficients. Finite truncations of these series are referred to as polynomial chaos (PC) approximations. This paper explores features and limitations of PC approximations. Metrics are developed to assess the accuracy of the PC approximation. A collection of simple, but relevant examples is examined in this paper. The number of terms in the PC approximations used in the examples exceeds the number of terms retained in most current applications. For the examples considered, it is demonstrated that (1) the accuracy of the PC approximation improves in some metrics as additional terms are retained, but does not exhibit this behavior in all metrics considered in the paper, (2) PC approximations for strictly stationary, non-Gaussian stochastic processes are initially nonstationary and gradually may approach weak stationarity as the number of terms retained increases, and (3) the development of PC approximations for certain processes may become computationally demanding, or even prohibitive, because of the large number of coefficients that need to be calculated. However, there have been many applications in which PC approximations have been successful.

On the accuracy of the polynomial chaos approximation for random variables and stationary stochastic processes.

Component mode synthesis as a framework for uncertainty analysis

A journal bearing with variable geometry for the suppression of vibrations in rotating shafts: Simulation, design, construction and experiment

The goal of this work is to develop deeper insight into the method of damping vibrations by means of parametric excitation in mechanical systems - employing the concept of the so-called parametric anti-resonance. Mechanical systems with simultaneously varying time-periodic stiffness, damping and inertia coefficients are examined. At least two vibration modes are necessary to achieve damping. For these minimum systems a thorough stability analysis is carried out using a perturbation technique. Parametric excitation may lead to a coupling of just two modes of a vibrating system, while the remaining modes are not affected. This coupling enables to transfer energy between modes and its subsequent mitigation. The results demonstrate that parametric excitation can be employed to extend significantly the area of stability in the parameter space of the system parameters. The proposed method shows potential in practical applications when a destabilization due to self-excitation occurs or when the damping of weakly damped systems shall be enhanced. The present book can be used as a comprehensive guide for designing a device for vibration suppression by parametric excitation.

Damping by Parametric Stiffness Excitation: Resonance and Anti-Resonance:

Improving stability and operation of turbine rotors using adjustable journal bearings

Stability investigations of vibration suppression employing the concept of actuators with a variable stiffness are presented. Systems with an arbitrary number of degrees of freedom with linear spring- and damping-elements are considered that are subject to self-excitation as well as parametric stiffness excitation. General conditions for full vibration suppression and conditions of instability are derived analytically by applying a singular perturbation of first and second order. The analytical predictions are compared for exemplary systems by numerical time integration and show a great improvement of former results. These basic results obtained can be used for accurate design of a control strategy for actuators.

Fadi Dohnal

Papers

Component mode synthesis as a framework for uncertainty analysis

A journal bearing with variable geometry for the suppression of vibrations in rotating shafts: Simulation, design, construction and experiment

Damping by Parametric Stiffness Excitation: Resonance and Anti-Resonance:

Improving stability and operation of turbine rotors using adjustable journal bearings

Averaging in vibration suppression by parametric stiffness excitation