Structure Borne Sound

Since structure-borne sound plays an important role in noise control, material testing and machine diagnosis, the relevant properties of the most important elements of a construction (plates, beams and shells) are investigated. Measurement techniques, equations of motion, formulas for wave speeds, resonance frequencies, impedances, transmission coefficients etc. are given. The different damping mechanisms and the radiation properties are treated. The statistical energy analysis (SEA) is also presented. This new edition has been enlarged to include also waves on orthotropic plates, and the vibration and radiation of cylindrical shells.

Structure-Borne Sound" is a thorough introduction to structural vibrations with emphasis on audio frequencies and the associated radiation of sound. The book presents in-depth discussions of fundamental principles and basic problems, in order to enable the reader to understand and solve his own problems. It includes chapters dealing with measurement and generation of vibrations and sound, various types of structural wave motion, structural damping and its effects, impedances and vibration responses of the important types of structures, as well as with attenuation of vibrations, and sound radiation from structures. For the third edition, the author fundamentally revised and newly organized the contents of the work. Nevertheless, the intention has been to preserve the style of the previous editions, namely to focus on the fundamentals enabling the reader to analyse further problems.

Suitable for both individual and group learning, Engineering Acoustics focuses on basic concepts and methods to make our environments quieter, both in buildings and in the open air. The author’s tutorial style derives from the conviction that understanding is enhanced when the necessity behind the particular teaching approach is made clear. He also combines mathematical derivations and formulas with extensive explanations and examples to deepen comprehension. Fundamental chapters on the physics and perception of sound precede those on noise reduction (elastic isolation) methods. The last chapter deals with microphones and loudspeakers. Moeser includes major discoveries by Lothar Cremer, including the optimum impedance for mufflers and the coincidence effect behind structural acoustic transmission. The appendix gives a short introduction on the use of complex amplitudes in acoustics.

Whcn the original German edition of this book first appeared in print, the undcrsigned was asked to review it for an English-language journal. In the course of this review process he was so struck by the book's unusual approach, as well as by the realization that no similar collection of information was available in English, that he conceived thc idea of undertaking this translation. Arrangements with the original authors and with the publisher were completed late in 1969; the translation task was begun at that. time and occupied nearly two and onc-half years-largcly because the undersigned's other professional act.ivities permitted him toderote only hisspare time to the translation effort. Because this passage of time also brought with it some advances in the state of t.he art, an attempt was made to include the most significant of these aclvances, as well as newer references and some minor correc tions, in the translatecl rersion. Except for these changes, which were macle with the enthusiastic endorsement and collaboration of the origi nal authors, the translatecl rersion remains very close to the original. In fact, the translator took special care to preserve not only the mean ing, but also the "flaror", of the original text. The translator is most grateful to Professor L. Cremer and Dr

As a comprehensive reference dedicated to sound and vibration in buildings, Building Acoustics and Vibration addresses the basic and advanced principles that can be used to solve practical and theoretical problems typically encountered in building and architectural acoustic practices. In addition, physical and mathematical concepts are introduced and developed sufficiently to make this publication a self-contained and up-to-date source of information for readers. Building Acoustics and Vibration is a must-have textbook for engineering students, engineers, and consultants involved in the sound, vibrations and building environment. With comprehensibility and versatility in the presentation of knowledge, this highly anticipated publication will easily fill the gap in the literature of building engineering and sciences, which presently lacks an authoritative guide on the theoretical and practical aspects of building acoustics and vibration.

Structure-borne sound sources are vibrational sources connected in some way to the building structure. The mechanical excitation of the building structure leads to sound radiation. This is an important source of annoyance in modern light-weight buildings. The prediction of the sound pressure level from structure-borne sound sources is highly complicated because of the complexity involved in the coupling between source and receiver structure. The current standard on characterisation of service equipment in buildings EN 12354-5, can deal with sources on heavy structures (high-mobility source) but to date, there is no engineering method available for the case of coupling between source and receiver. A case study of a washing machine on a wooden joist floor is investigated in this thesis. In the first part, measurements in the coupled state are conducted. It is shown that the normal components are sufficient to predict the sound pressure level. However, this only applies to the coupled state. In the second part, a true prediction is calculated from independently measured source and receiver quantities. The difference between predicted and directly measured sound pressure level leads to considerable errors of up to 20 dB at low frequencies. This shows that the normal components are not sufficient to predict the coupling between a washing machine and a wooden floor.

This textbook provides materials for an introductory course in Engineering Acoustics for students with a basic knowledge of mathematics. The contents are based on extensive teaching experience at the graduate level. Each of the 14 main chapters deals with a well-defined topic and represents the material for a two-hour lecture. The chapters alternate between more theoretical and more application-oriented concepts. The presentation is organized to be suitable for self-study as well. For this third edition, the complete text and many figures have been revised. Several current amendments take account of advancements in the field. Further, a completely new chapter has been added which presents approaches and solutions to all assigned exercise problems. The new chapter offers the opportunity to explore the underlying theoretical background in more detail. However, the study of the problems and their proposed solutions is no prerequisite for comprehending the material presented in the book's lecture part.