Theory, practice and application mechanical engineering research. System analysis operational modal analysis theory frequency domain decomposition, fdd stochastic subspace identification, ssi state space models timefrequency analysis applications and use of oma test planning, testing and data quality control application examples. In the first part modal analysis, its theoretical and experimental. Modal analysis provides an overview of the limits of the response of a system. These modes are numbered, from 1, in order of increasing frequency. This book gives an introduction to mechanical systems and vibration.
Modal analysis theory and testing ward heylen, stefan. Pdf there is given the theoretical background of the modal analysis in this paper. Division of production engineering, machine design and automation. It assumes that the reader has a basic understanding of vibration terminology and theory. Modal analysis theory and testing ward heylen, stefan lammens, paul sas katholieke universiteit leuven, faculty of engineering, department of mechanical engineering, division of production engineering, machine design and automation, 1998 modal analysis. The implications of the model structure, in the latter case, on the application of modal testing are presented, as this is a point of great importance when experimental modal analysis is employed for rotating structures. In the modal analysis of plane frames the main aim is to determine the natural mode shapes and frequencies of an object or.
It define the theoretical background of modal analysis while other models of modal analysis exist, for example models with different damping, excitation and other examples of calculation of modal analysis. As shown in the preceding chapter, the motion of a dynamic structure or system may be represented by a set of simultaneous differential equations using some discretization scheme, such as the finite element method, if necessary. In simulation, performing a free vibration analysis is similar to a linear static analysis. Pappa nasa langley research center hampton, virginia summary structural materials in the form of graphite epoxy composites with embedded rubber layers are being used to reduce vibrations in rocket motor tubes. Finiteelement vibration analysis and modal testing of. Basics of modal testing and analysis crystal instruments. This article what is modal analysis and why is it necessary gives a more detailed answer to your question, but in short. Modal analysis theory and testing ward heylen, stefan lammens, paul sas. Overview of modal testing iust,modal testing lab,dr h ahmadian philosophy of modal testing integration of three components. However, many times the theory is just a little too much to handle and some of the concepts can be. It is assumed that the user has already covered chapter 4 linear static structural analysis prior to this section.
The paper presents the experimental and analytical modal analysis of a crankshaft. Methodology for correlating experimental and finite element. Some of the more organic theories considered in model theory other than set theory, which, from what ive seen, seems to be quite distinct from mainstream model theory are those which arise from algebraic structures theories of abstract groups, rings, fields and real and complex analysis theories of expansions of real and complex fields, and sometimes both. Applications of model theory to analysis mathematics. This book gives a good introduction to the theory as well as all practical aspects of experimental modal analysis. Structural testing part 2, modal analysis and simulation br0507. Experimental and analytical modal analysis of a crankshaft. Objectives engineers and designers need to understand and determine the magnitude of vibration and modal charac. Finiteelement vibration analysis and modal testing of graphite epoxy tubes and correlation between the data b. Cunhaambient vibration retesting and operational modal analysis of the humber. Abstract this papers focus is on experimental structural analysis using contemporary testing techniques for a small unmanned aerial vehicle suav. Theory is presented as needed to enhance the logical development of ideas. Structural testing part 2, modal analysis and simulation.
Ae 568 experimental analysis of vibrating structures. Modal analysis theory and testing, kuleuven isbn 907380261x. Modal analysis is a standard technique, welldocumented in the literature. Modal testing modal assurance criterion mac services. There are occasional hints at the rst and the fourth, leaving the others largely untouched. With real structures we will usually have lit tle or no knowledge of the mass, stiffness and damping distributions. Modal analysis theory and testing 1998 edition open. Today, impact testing or bump testing has become widespread as a fast and economical means of finding the modes of vibration of a machine or structure. Pdf modal analysis casestudy of testing on a double. It also enables us to construct a powerful tool, the modal model, with which we can investigate the effects of. Introduction the aim of the course is to understand and determine the magnitude of vibration and modal characteristics of a structural system. Theory, practice, and application, 2nd edition by d.
Chapter 2 and 3 which is the bulk of the note describes the. Theory, practice and application mechanical engineering research studies. Dec 15, 2009 modal analysis theory and testing by ward heylen, 1998, katholieke universiteit leuven, faculty of engineering, dept. Modal analysis theory and testing by ward heylen, 1998, katholieke universiteit leuven, faculty of engineering, dept. Semke unmanned aircraft systems engineering laboratory school of engineering and mines university of north dakota grand forks, nd 58202 abstract. According to the dynamic theory and characteristics of the bridge modal analysis theories and methods for bridge were introduced which mainly included solving the nature frequency, mode shape, and damping ratio with the rayleighritz method, subspace iteration method. The experimental modal analysis ema testing technique provides a great deal more. Theory of vibration accurate vibration measurement realistic and detailed data analysis examples. In general system theory terms we are speaking of systems with 4 to 8 inputs, over. Proceedings of the nato advanced study institute, sesimbra, portugal, 315 may, 1998.
This paper is only general entry to the modal analysis. The objective of modal identification then becomes determining the posterior probability density function pdf of the modal parameters for given data and modeling assumptions. The reader will gain a sound physical understanding of modal analysis and be able to carry out an effective modal survey with confidence. This is an example of modal analysis applied on a part by using fea module in autodesk inventor 2014.
Overview of modal testing iust, modal testing lab,dr h ahmadian philosophy of modal testing integration of three components. The determination of these modal parameters may be by the way of either a theoretical analytical or numerical approach or an experimental approach and termed theoretical modal analysis and experimental modal analysis, respectively. Modal analysis theory and testing 1998 edition open library. Un1v1 1 lty oi s11 ijk mod 1t tino th ory nd prnctic du11110 thil 1970 o now hra11ch of v1brnt1on engin1 ormg wa v lop d, 11compn mg the rnost powcrffji aspect of both xj 1 rl11u1111n1 r111d anllly111 nl t1 clt111q11os. Steffen, jr federal university of uberlandia, school of mechanical engineering, brazil keywrds. And the application of bridge modal shape sequences and frequencies with their changes were illustrated in the diagnosis. The modal domain the modal domain is one perspective for understanding structural vibrations. Application of modal testing and analysis techniques on a suav. This work is in continuation with our previous work, published in ijsrd, volume 3, issue 2, entitled, modal analysis casestudy of testing on a double storey laboratory floor. Stochastic subspace identification, ssi state space models timefrequency analysis applications and use of oma test planning, testing and data quality control application examples. Objectives engineers and designers need to understand and determine the magnitude of vibration and modal characteristics of a structural system in its operating conditions.
May 24, 2015 3501854 djewinsmodaltestingtheoryandpractice 1. Modal analysis theory and testing university of toronto. Request pdf modal analysis theory waves on a stringmatrix formulationseigenvalues and. The modal analysis is useful when we want to find out what are the resonant frequencies of a rigid body when a certain vibration occurs. Tracking the history of modal analysis, the conception of vibration modes dates back. Ieee instrumentation and measurement technology conference budapest, hungary, may 2123, 2001 structural dynamics modeling using modal analysis. Modal analysis for structural validation course no. Modal analysis theory and testing ward heylen stefan lammens paul sas division of production engineering, machine design and automation katholieke universiteit leuven. Modal analysis is an increasingly more important engineering tool that was first applied around 1940 in the search for a better understanding of aircraft dynamic behaviour. Most times, it is impossible to describe this simply and some of the basic underlying theory needs to be addressed in order to fully explain some of these concepts. Modal analysis of the data obtained from structural testing, provides us with a definitive description of the response of a structure, which can be evaluated against design specifi cations. Quality and suitability of data for process excitation type understanding of forms and trends of plots. Measurement and signal analysis is the culmination of the authors more than two decades of teaching and research experience in these areas. The experimental modal analysis ema testing technique provides a great deal more information about the inservice condition of a bridge under test than is possible from.
A modal analysis calculates the undamped natural modes of a system, characterised by their modal frequency and mode shape. This approach improves the efficiency of the test process, ensuring that the test article is neither. Application of modal testing and analysis techniques on a suav kaci j. Modal analysis theories and methods for bridge scientific. Application of modal testing and analysis techniques on a. Testing was performed to find the bending and torsional modes of the wings and tail utilizing multiple methods. The test result obtained with one type of excitation can be used for predicting the. Modal analysis is one of the most powerful tools available to the engineer for the dynamic analysis of structures. Free vibration analysis procedure free vibration with prestress analysis procedure.
Development has been rapid and spans the identification and evaluation of vibration phenomena, the validation, correction and updating of analytical models and the assessment of structural integrity. Experimental modal analysis is a vibration testing technique for determining the natural frequencies, mode shapes and damping ratios of a structure. Jlab 12gev cavities tuning sensitivity 300 hz micron low frequency oscillations cause cavity target frequency to vary 1497. During modal testing, an instrumented hammer, electromagnetic shaker or piezoelectric actuator is used to excite vibration of the test article.
A pretest analysis procedure is employed to guide the execution of tests used in the correlation process. Pdf theoretical basis of modal analysis researchgate. Chapter 1 provides a brief overview of structural dynamics theory. Methodology for correlating experimental and finite. An overview of the fundamentals of modal analysis springerlink. However, many times the theory is just a little too much to handle and some of the. For an introduction to vibration testing and analysis, refer to crystal instruments basics of structural vibration testing and analysis.
The effective material and geometrical properties are measured, and the dynamic behavior is investigated through impact testing. Katholieke universiteit leuven, faculty of engineering, dept. Vibration, estimation, frequency domain, modal analysis, modal parameters, natural. Introduction the aim of the course is to understand and determine the magnitude of vibration and modal. Modal analysis is the study of the dynamic properties of systems in the frequency domain. Comparison of finite element method and modal analysis of violin top plate ye lu music technology area, department of music research schulich school of music mcgill university montreal, canada june 20 a thesis submitted to mcgill university in partial ful llment of the requirements for the degree of master of arts in music technology. Katholieke universiteit leuven, faculty of engineering, department of mechanical engineering, division of production engineering, machine design and automation, 1998 modal analysis. The three main phases of modal testing the theoretical basis of vibration, accurate measurement of vibration controlled testing conditions, realistic and detailed data analysis signal processing, range of. Comparison of finite element method and modal analysis of. Examples would include measuring the vibration of a cars body when it is attached to a shaker, or the noise pattern in a room when excited by a loudspeaker.
874 665 876 1448 117 1272 948 1551 1036 132 1 1182 612 1304 57 18 1257 419 134 1633 1646 1480 1332 1452 53 115 899 853 1188 530 1395 968 1277 514 944 264