Preface to the Reprinted Edition
The Acoustical Society of America is reprinting this book, along with my subsequently published one, "Vibration of Shells," as a service to the technical community with no commercial expectations. I am very pleased that they are doing this, for both books have been in great demand, and have been out of print for a long time.

For example, 5100 copies of "Vibration of Plates" were published by the U.S. Government Printing Office in 1969. 100 copies were hard bound, and were given to key people in the technical community. Of the remaining 5000 soft-bound copies, approximately 1000 were distributed to NASA and other government personnel and technical libraries, and the remainder were made available inexpensively to the general public by the Superintendent of Documents. Within three years they were all bought. Hearing this, in 1974 I approached the NASA publication personnel in Washington to get GPO to reprint the book. They were told by GPO that it would not be reprinted because of "insufficient demand!" Such is bureaucratic logic. Being at a low point in my life at that time, and not willing to fight the battle myself to get the book reprinted, I let the matter drop.

I wrote this book because I felt that there was a great need for it. At least I needed it, and therefore thought that many others did, too. In this respect my expectations have been exceeded. During the intervening quarter century since it appeared, I have received scores of letters and phone calls from people, often asking questions, who are grateful for its existence. A study of Science Citation Index in 1987 showed that during the preceding seven years, "Vibration of Plates" was cited by others 226 times in the published literature--an average of 32 times per year. Thus, I feel that my time was well spent in writing this book.

Although this book was first published in 1969, its writing was finished in 1966. In the original Preface, reasonable completeness of results published in the scientific and technical literature through 1965 was claimed. Conversely, only a few last-minute additions were made of results published in 1966. Subsequently, I have uncovered only a few significant references which are not included among the 500 in this work, although they should have been. So, I am satisfied with its "reasonable completeness."

However, an enormous number of publications dealing with free vibrations of plates have appeared since 1965. I have 1500 additional ones in my file cabinets! The upsurge in research and writing on the subject began several years after the book first appeared, when many researchers realized what specific cases have received little or no attention, and continues unabated today. Most of this later research deals with what I call "complicating effects," beyond what is governed by classical, isotropic, thin plate theory. These complicating effects are anisotropy (Chapter 9), inplane forces (10), variable thickness (11), and other considerations (12) such as the effects of surrounding media (e.g., water, air), large (nonlinear) deflections, shear deformation and rotary inertia, and nonhomogeneity. The largest increase in recent publications is in the topic area of nonhomogeneity, where hundreds of papers examining laminated composite plates have appeared.

It was stated in the original Preface that I intended to "write a supplement to this volume after a few years have elapsed." Indeed, this is why I have continued to collect relevant references. So far, I have not been able to make the time available to do so, but I still intend to. Certainly with all the new research results appearing since 1965, such a work is greatly needed. But it will have to be more than a "supplement." I foresee a complete rewriting, with frequencies, frequency determinants, eigenfunctions, nodal patterns, and mode shapes, summarized in four volumes. Of course, this very ambitious project will require much time. In the meantime I would continue to appreciate receiving relevant information from researchers, especially that not easily available in the well known journals (e.g., reports, theses, conference papers).

Most of the literature appearing since 1965 may be found summarized in a set of review articles which I wrote for Shock and Vibration Digest: Vol. 9, No. 10, pp. 13-24 (1977); Vol. 10, No. 12, pp. 21-35 (1978); Vol. 13, No. 9, pp. 11-22 and No. 10, pp. 19-36 (1981); and Vol. 19, No. 2, pp. 11-18 and No. 3, pp. 10-24 (1987). An additional 156 publications for the period 1966-1972 are also available from the reference list of a short course on plate vibrations that I taught in 1979.

As could be expected, some errors did appear in this work. I discovered some while using the book hundreds of times in the past 24 years. Others were pointed out by researchers in letters and phone calls. A total of sixteen errors were found that have been corrected in this reprinted edition. Corrections are on pages, 5, 10, 11, 14, 29, 53, 60, 67, 77, 105, 144, 262, 277, and 285.

I want to thank Dr. Mauro Pierucci of San Diego State University who, as Chairman of the Book Committee of the Acoustical Society of America, initiated this reprinting effort and followed it through to its fruition.

Arthur W. Leissa
The Ohio State University
May 10, 1993