Modeling And Analysis Of Passive Vibration Isolation Systems

Modeling and Analysis of Passive Vibration Isolation Systems discusses a wide range of dynamic models that can be used for the design and analysis of passive vibration isolation systems. These models range from linear viscoelastic single degree-of-freedom systems to multiple degree-of-freedom nonlinear systems. They can be used to evaluate hyperelasticity and creep, and to represent the inertia effect for an evaluation of vibroacoustic characteristics at high frequencies. This book also highlights specific nonlinear behavior, displacement-limiting designs, hyperelastic behavior, and characteristics associated with elastomeric materials for each model. It also identifies key attributes, limitations, and constraints, providing a holistic reference that can be used for the design and analysis of passive vibration isolators. Modeling and Analysis of Passive Vibration Isolation Systems serves as a reference for engineers and researchers involved in the design, development, modeling, analysis, and testing of passive vibration isolation systems and as a reference for a graduate course in vibration modeling and analysis. Outlines the use of multiple models for optimal passive vibration isolation system design Discusses the effects system design has on subsequent product development components and parameters Includes applied examples from the automotive, aerospace, civil engineering and machine tool industries Presents models that can be extended or modified to investigate different means of passive isolation, nonlinearities, and specific design configurations Considers specific elastomer characteristics such as Mullins and Payne effects for theoretical modeling and analysis

Modeling and Analysis of Dynamic Systems, Third Edition introduces MATLAB®, Simulink®, and SimscapeTM and then utilizes them to perform symbolic, graphical, numerical, and simulation tasks. Written for senior level courses/modules, the textbook meticulously covers techniques for modeling a variety of engineering systems, methods of response analysis, and introductions to mechanical vibration, and to basic control systems. These features combine to provide students with a thorough knowledge of the mathematical modeling and analysis of dynamic systems. The Third Edition now includes Case Studies, expanded coverage of system identification, and updates to the computational tools included.

Modeling and Analysis of Dynamic Systems, Second Edition introduces MATLAB®, Simulink®, and SimscapeTM and then uses them throughout the text to perform symbolic, graphical, numerical, and simulation tasks. Written for junior or senior level courses, the textbook meticulously covers techniques for modeling dynamic systems, methods of response analysis, and provides an introduction to vibration and control systems. These features combine to provide students with a thorough knowledge of the mathematical modeling and analysis of dynamic systems. See What’s New in the Second Edition: Coverage of modeling and analysis of dynamic systems ranging from mechanical to thermal using Simscape Utilization of Simulink for linearization as well as simulation of nonlinear dynamic systems Integration of Simscape into Simulink for control system analysis and design Each topic covered includes at least one example, giving students better comprehension of the subject matter. More complex topics are accompanied by multiple, painstakingly worked-out examples. Each section of each chapter is followed by several exercises so that students can immediately apply the ideas just learned. End-of-chapter review exercises help in learning how a combination of different ideas can be used to analyze a problem. This second edition of a bestselling textbook fully integrates the MATLAB Simscape Toolbox and covers the usage of Simulink for new purposes. It gives students better insight into the involvement of actual physical components rather than their mathematical representations.

In this work, the effect of pseudoelastic response of shape memory alloys (SMAs) on passive vibration isolation has been investigated. This study has been conducted by developing, modeling, and experimentally validating a SMA-based vibration isolation device. This device consists of layers of preconstrained SMA tubes undergoing pseudoelastic transformations under transverse dynamic loading. These SMA tubes are referred to as SMA spring elements in this study. To accurately model the nonlinear hysteretic response of SMA tubes present in this device, at first a Preisach model (an empirical model based on system identification) has been adapted to represent the structural response of a single SMA tube. The modified Preisach model has then been utilized to model the SMA-based vibration isolation device. Since this device also represents a nonlinear hysteretic dynamical system, a physically based simplified SMA model suitable for performing extensive parametric studies on such dynamical systems has also been developed. Both the simplified SMA model and the Preisach model have been used to perform experimental correlations with the results obtained from actual testing of the device. Based on the studies conducted, it has been shown that SMA-based vibration isolation devices can overcome performance trade-offs inherent in typical softening spring-damper vibration isolation systems. This work is presented as a two-part paper. Part I of this study presents the modification of the Preisach model for representing SMA pseudoelastic tube response together with the implemented identification methodology. Part I also presents the development of a physically based simplified SMA model followed by model comparisons with the actual tube response. Part II covers extensive parametric study of a pseudoelastic SMA spring-mass system using both models developed in Part I.

Constitutive Models for Rubber XI is a comprehensive compilation of both the oral and poster contributions to the European Conference on Constitutive Models for Rubber. This 11th edition, held in Nantes (France) 25-27th June 2019, is the occasion to celebrate the 20th anniversary of the ECCMR series. Around 100 contributions reflect the state-of-the-art in the mechanics of elastomers. They cover the fields of: Material testing Constitutive modelling and finite element implementation Micromechanical aspects, and Durability (failure, fatigue and ageing) Constitutive Models for Rubber XI is of interest for developers and researchers involved in the rubber processing and CAE software industries, as well as for academics in nearly all disciplines of elastomer mechanics and technology.

In order to develop innovative products, to reduce development costs and the number of prototypes and to accelerate development processes, numerical simulations become more and more attractive. As such, numerical simulations are instrumental in understanding complicated material properties like chemical ageing, crack propagation or the strain- and temperature-induced crystallisation of rubber. Therefore, experimentally validated and physically meaningful constitutive models are indispensable. Elastomers are used for products like tyres, engine and suspension mounts or seals, to name a few. The interest in modelling the quasi-static stress-strain behaviour was dominant in the past decades, but nowadays the interests also include influences of environmental conditions. The latest developments on the material behaviour of elastomers are collected in the present volume. Constitutive Models for Rubber X is a comprehensive compilation of nearly all oral and poster contributions to the European Conference on Constitutive Models for Rubber (Munich, 28-31 August 2017). The 95 highly topical contributions reflect the state of-the-art in material modelling and testing of elastomers. They cover the fields of material testing and processing, filler reinforcement, electromagnetic sensitive elastomers, dynamic properties, constitutive modelling, micromechanics, finite element implementation, stress softening, chemical ageing, fatigue and durability. In the area of rubbery materials and structures, applied research will play an important role also in the coming decades. Constitutive Models for Rubber X is of interest to developers and researchers involved in the rubber processing and CAE software industries, as well as for academics in nearly all disciplines of engineering and material sciences.

This monograph develops a generalised energy flow theory to investigate non-linear dynamical systems governed by ordinary differential equations in phase space and often met in various science and engineering fields. Important nonlinear phenomena such as, stabilities, periodical orbits, bifurcations and chaos are tack-led and the corresponding energy flow behaviors are revealed using the proposed energy flow approach. As examples, the common interested nonlinear dynamical systems, such as, Duffing’s oscillator, Van der Pol’s equation, Lorenz attractor, Rössler one and SD oscillator, etc, are discussed. This monograph lights a new energy flow research direction for nonlinear dynamics. A generalised Matlab code with User Manuel is provided for readers to conduct the energy flow analysis of their nonlinear dynamical systems. Throughout the monograph the author continuously returns to some examples in each chapter to illustrate the applications of the discussed theory and approaches. The book can be used as an undergraduate or graduate textbook or a comprehensive source for scientists, researchers and engineers, providing the statement of the art on energy flow or power flow theory and methods.

In this dissertation, an analytical investigation on active, semi-active and passive vibration control mechanisms is presented in order to achieve improved shock and vibration isolation of mechanical systems, especially ground vehicle applications. A hybrid active vibration isolation system, incorporating an electro-magnetic force generator along with passive damping and spring elements, is mathematically modeled based on fundamental physical laws and taking into account the generator dynamics. Complete vibration isolation characteristics of the hybrid active control system are evaluated for various feedback variables and control schemes, using numerical simulations. Influence of the force generator dynamics on vibration isolation performance is illustrated through the simulation results. A concept of tunable pressure limiting modulation is proposed in hydraulic damper systems. A hydraulic orifice damper is modified by using the proposed tunable pressure limiting modulation to achieve variable damping in vibration isolation systems, without requiring any external energy source, sophisticated control devices and feedback instrumentation that are essential for active and semi-active isolators. The fluid flow equations are employed to develop the nonlinear mathematical model of the hydraulic damper, incorporating the fluid and mechanical compliance, and the dynamics of the pressure limiting mechanism. The computer simulation reveals that the shock and vibration isolation performance of the tunable pressure limited hydraulic damper systems is comparable to that of the semi-active 'on-off' vibration control systems. A generalized harmonic linearization technique, based on a principle of energy similarity of dynamic elements, is proposed to derive equivalent linear representations of both nonlinear damping and spring elements, in the frequency domain. An analysis of the nonlinear in-plane vehicle model, with air-springs, orifice damping and pressure limiting modulation due to tunable hydraulic shock absorbers, is carried out to establish the stochastic response to random road inputs in terms of power spectral density, and to illustrate the improved vehicle ride performance due to tunable shock absorbers. An interconnected hydro-pneumatic suspension with tunable pressure limiting mechanism is presented to achieve improved vehicle ride and handling performance. Analysis of a roll plane model of a vehicle employing the tunable interconnected suspension shows that the connections of fluid flow within the interconnected suspension provide an enhanced static roll stability; while the tunable pressure limiting modulation between the strut and the accumulator of each suspension unit offers an improved vehicle ride performance.