Computational Techniques Of Rotor Dynamics With The Finite Element Method

For more than a century, we have had a firm grasp on rotor dynamics involving rigid bodies with regular shapes, such as cylinders and shafts. However, to achieve an equally solid understanding of the rotational behavior of flexible bodies-especially those with irregular shapes, such as propeller and turbine blades-we require more modern tools and m

For more than a century, we have had a firm grasp on rotor dynamics involving rigid bodies with regular shapes, such as cylinders and shafts. However, to achieve an equally solid understanding of the rotational behavior of flexible bodies—especially those with irregular shapes, such as propeller and turbine blades—we require more modern tools and methods. Computational Techniques of Rotor Dynamics with the Finite Element Method explores the application of practical finite element method (FEM)-based computational techniques and state-of-the-art engineering software. These are used to simulate behavior of rotational structures that enable the function of various types of machinery—from generators and wind turbines to airplane engines and propellers. The book’s first section focuses on the theoretical foundation of rotor dynamics, and the second concentrates on the engineering analysis of rotating structures. The authors explain techniques used in the modeling and computation of the forces involved in the rotational phenomenon. They then demonstrate how to interpret and apply the results to improve fidelity and performance. Coverage includes: Use of FEM to achieve the most accurate computational simulation of all gyroscopic forces occurring in rotational structures Details of highly efficient and accurate computational and numerical techniques for dynamic simulations Interpretation of computational results, which is instrumental to developing stable rotating machinery Practical application examples of rotational structures’ dynamic response to external and internal excitations An FEM case study that illustrates the computational complexities associated with modeling and computation of forces of rotor dynamics Assessment of propellers and turbines that are critical to the transportation and energy industries Useful to practicing engineers and graduate-level students alike, this self-contained volume also serves as an invaluable reference for researchers and instructors in this field. CRC Press Authors Speak Louis Komzsik introduces you to two books that share a common mathematical foundation, the finite element analysis technique. Watch the video.

The design and construction of rotating machinery operating at supercritical speeds was, in the 1920s, an event of revolutionary importance for the then new branch of dynamics known as rotor dynamics. In the 1960s, another revolution occurred: In less than a decade, imposed by operational and economic needs, an increase in the power of turbomachinery by one order of magnitude took place. Dynamic analysis of complex rotor forms became a necessity, while the importance of approximate methods for dynamic analysis was stressed. Finally, the emergence of fracture mechanics, as a new branch of applied mechanics, provided analytical tools to investigate crack influence on the dynamic behavior of rotors. The scope of this book is based on all these developments. No topics related to the well-known classical problems are included, rather the book deals exclusively with modern high-power turbomachinery.

The purpose of this book is to give a basic understanding of rotor dynamics phenomena with the help of simple rotor models and subsequently, the modern analysis methods for real life rotor systems. This background will be helpful in the identification of rotor-bearing system parameters and its use in futuristic model-based condition monitoring and, fault diagnostics and prognostics. The book starts with introductory material for finite element methods and moves to linear and non-linear vibrations, continuous systems, vibration measurement techniques, signal processing and error analysis, general identification techniques in engineering systems, and MATLAB analysis of simple rotors. Key Features: • Covers both transfer matrix methods (TMM) and finite element methods (FEM) • Discusses transverse and torsional vibrations • Includes worked examples with simplicity of mathematical background and a modern numerical method approach • Explores the concepts of instability analysis and dynamic balancing • Provides a basic understanding of rotor dynamics phenomena with the help of simple rotor models including modern analysis methods for real life rotor systems.

A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods. Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book: Covers examples of different computation methods, presents results, and discusses limitations of each Reviews the fundamentals of bearing and bearing dynamic coefficients Includes illustrations from the numerical analysis and results of the experimental research Offers myriad practical examples and a companion website Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.

This second edition includes eleven new sections based on the approximation of matrix functions, deflating the solution space and improving the accuracy of approximate solutions, iterative solution of initial value problems of systems of ordinary differential equations, and the method of trial functions for boundary value problems. The topics of th

The purpose of the calculus of variations is to find optimal solutions to engineering problems whose optimum may be a certain quantity, shape, or function. Applied Calculus of Variations for Engineers addresses this important mathematical area applicable to many engineering disciplines. Its unique, application-oriented approach sets it apart from the theoretical treatises of most texts, as it is aimed at enhancing the engineer’s understanding of the topic. This Second Edition text: Contains new chapters discussing analytic solutions of variational problems and Lagrange-Hamilton equations of motion in depth Provides new sections detailing the boundary integral and finite element methods and their calculation techniques Includes enlightening new examples, such as the compression of a beam, the optimal cross section of beam under bending force, the solution of Laplace’s equation, and Poisson’s equation with various methods Applied Calculus of Variations for Engineers, Second Edition extends the collection of techniques aiding the engineer in the application of the concepts of the calculus of variations.

This book is written as an introduction to rotor-bearing dynamics for practicing engineers and students who are involved in rotordynamics and bearing design. The goal of this book is to provide a step-by-step approach to the understanding of fundamentals of rotor-bearing dynamics by using DyRoBeS(c) . Therefore, the emphasis of this book is on the basic principals, phenomena, modeling, and interpretation of the results. Numerous examples, from a single-degree-of-freedom system to complicated industrial rotating machinery, are employed throughout this book to illustrate these fundamental dynamic behaviors. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures. The book begins with a brief discussion of the mathematical modeling of physical dynamic systems and an overview of the basic vibration concepts in Chapter 1. The coordinate systems and the kinematics of the rotor motion are presented in Chapter 2. A simple two-degrees-of-freedom rotor system, the Laval-Jeffcott rotor model, is utilized in Chapter 3 to demonstrate many important phenomena in rotordynamics. This simple 2DOF model provides many valuable physical insights into more practical and complicated systems. Chapter 4 discusses the rotating disk equations and rigid rotor dynamics. Chapter 5 covers the finite element formulation for a rotating shaft element. Chapter 6 deals with various types of bearings, dampers, seals and other interconnection components. All the reaction forces from these components are non-linear in nature. The concept of linearization around the static equilibrium is discussed. Chapter 7 summarizes the lateral vibration study with several practical examples. Various solution techniques and interpretation of the results are discussed. Chapter 8 is devoted to the important subject of torsional vibration. Finally, a brief description of the balancing method, influence coefficient method is presented in Chapter 9.