The text is based on many lectures on the subject of structural dynamics given at numerous institutions and thus will be an accessible and practical aid to students of the subject. Li and Chen also cover advanced topics, including the theory of and elaborate numerical methods for probability density evolution analysis of stochastic dynamical systems, reliability-based design, and performance control of structures. Clougj factors must be considered in the selection of this interval: The relation between damping ratio and frequency ratio may be depicted graphically as a circle of unit radius as shown in Fig. The finite-element type of idealization is applicable to structures of all types: The entire loading history can be considered to consist of a succession of such short impulses, each producing its own differential response of the form of Eq. The key assets of the book include comprehensive coverage of both the traditional and state-of-the-art numerical techniques of response analysis, such as the analysis by numerical integration of the equations of motion and analysis through frequency domain.
The authors outline the fundamental concepts of random variables, stochastic process and random field, and orthogonal expansion of random functions. Inertial and elastic forces are not explicitly involved in this principle; instead, variations of kinetic and potential energy terms are utilized. Scott MacKenzie and Raphael C. By successive illustration of these three steps in the solution of each problem, the student must be led and encouraged to approach the solution of his own engineering problems in a similar way or in similar manner with a desired degree of accuracy in the final result. However, usually the entire time-history of response is required so that one must evaluate A n for successive values of N until the desired time-history of response is obtained.
Figure illustrates this type of behavior for a formulation where it is assumed that the stryctures acceleration is the average of the initial and the final values attained during the step. Stochastic Dynamics of Structures presents techniques for researchers and graduate students in a wide variety of engineering fields: civil engineering, mechanical engineering, aerospace and aeronautics, marine and offshore engineering, ship engineering, and applied mechanics. Clearly, the analysis requires qnd than three time steps per vibration period of the structure if the response is to be defined adequately, and in most earthquake response analyses a considerably shorter time step also must be adopted to permit effective definition of the earthquake input. The text includes many topics encompassing the theory of structural dynamics and the application of this theory regarding earthquake analysis, response, and design of structures. To demonstrate how damping can be included in the nu- merical evaluation of the Duhamel integral, the response analysis of structhres system of Fig. However, by means of a Fourier analysis any periodic loading can be represented as the sum of a series of simple harmonic components; dynamcis, in principle, the analysis of response to any periodic loading follows the same general procedure. The topics covered include: formulation of the equations of motion for single- as well as multi-degree-of-freedom discrete systems using the principles of both vector mechanics and analytical mechanics; free vibration response; determination of frequencies and mode shapes; forced vibration response to harmonic and general forcing functions; dynamic analysis of continuous systems;and wave propagation analysis.
The book is integrated by also comprising several useful appendices, and an exhaustive list of references; it will be an indispensable tool for students, researchers, and practitioners endeavoring in its thematic field. The theoretical developments are properly supplemented by examples from earthquake, wind, and ocean engineering. All books are in clear copy here, and all files are secure so don't worry about it. It will be shown later in Chapter 10 that these interpolation functions are cubic hermitian polynomials. The large number of illustrative examples and exercise problems are of great assistance in improving clarity and enhancing reader comprehension. In most cases, an approximate analysis in- volving only a limited number dynamids degrees of freedom will provide sufficient accuracy; thus, the problem can be reduced to the determination of the time-histories of these se- lected displacement components.
Readers will gain insight into core concepts such as stochastic process models for typical dynamic excitations of structures, stochastic finite element, and random vibration analysis. Emphasis is also given to the subject of seismic loading. The university training in such fundamental discipline must seek to build a strong foundation and to illustrate the application of the used methods to practical engineering problems. Please click button to get dynamics of structures book now. Plots of the time-histories of spring-force response for the undamped and damped cases treated in Examples E and E, respectively, are shown in Fig. The importance of these disciplines in the preparation of young structural engineers for work in the practice cannot be overemphasized. The text aims to benefit students and engineers in the civil, mechanical and aerospace sectors.
. No prior knowledge of structural dynamics is assumed and the manner of presentation is sufficiently detailed and integrated, to make the book suitable for self-study by students and professional engineers. The rotating-vector representation of Eq. The maximum response is then the vector sum of the two orthogonal components in the resulting free-vibration equation. Then, the equations of motion are obtained by separately introducing a virtual displacement pattern corresponding to each degree of freedom and equating the work done to zero.
The text aims to benefit students and engineers in the civil, mechanical, and aerospace sectors. In all fields of structural mechanics, the impact of good design of a room is very important to its strength, its life and its use in service. In principle, each interpo- lation function cllugh be any curve which is internally continuous and which satisfies the geometric displacement condition imposed by the nodal displacement. Dynamics of Structures: Ray W. This site is like a library, you could find million book here by using search box in the widget. If the weight of the console is lb, determine the stiffness of the vibration isolation system required to reduce the vertical-motion amplitude of the console to 0.
Generating response using the Duhamel or convolution integral is one means of obtaining response through the time domain. Practicing engineers will benefit from the concise review of random vibration theory and the new methods introduced in the later chapters. For this reason only the undamped response to impulsive loads will be considered in this chapter. We now establish the relation between these constants by expressing each of them in terms of its real and imaginary components: This corresponds to Point d in Fig. Reinvent yourself and grow radical influence. The Fourier coefficients of Eq.
Clearly the accuracy and compu- tational effort increase with the complexity of the numerical integration procedure. Beyond the traditional concepts, they also discuss theoretical tools of recent currency such as the Karhunen-Loeve expansion, evolutionary power spectra, etc. Ductile Design of Steel Structures, 2nd Edition. While the average power input at fa is somewhat less than one -half the peak power input and the average power input at fa is somewhat greater, the mean value of these two averaged inputs is very close to one-half the peak average power input. Uploader: Date Added: 23 May 2013 File Size: 27. The solution of a structural engineering problem usually consists of three basic steps: the simplification to such a state of idealization that it can be expressed in allegorical or geometrical form, the solution of this mathematical form, and the interpretation of the results of the solution in terms of the engineering needs.
Numerous case studies are given to provide the reader with a deeper insight into the practicalities of the area, and the solutions to these case studies are given in terms of real-time and frequency in both geometric and modal spaces. The development of the engineer's art requires considerable effort to constantly improve structural design techniques. It covers systems with both single and multiple degrees-of-freedom. You can get any if you can submit email. The goal is to get the appropriate forms of a part in minimizing a given criterion.