My coauthor Robert Caddell died in 1990. I have greatly missed interacting with him.
The biggest changes from the second edition are an enlargement and reorganization
of the last third of the book, which deals with sheet metal forming. Changes have been
made to the chapters on bending, plastic anisotropy, and cup drawing. An entire chapter
has been devoted to forming limit diagrams. There is one chapter on various aspects
of stampings, including the use of tailor-welded blanks, and another on other sheetforming
operations, including hydroforming of tubes. Sheet testing is covered in a
separate chapter. The chapter on sheet metal properties has been expanded to include
newer materials and more depth on aluminum alloys.
In addition, some changes have been made to the chapter on strain-rate sensitivity.
A treatment of friction and lubrication has been added. A short treatment of swaging
has been added. End-of-chapter notes have been added for interest and additional
end-of-chapter references have been added.
No attempt has been made in this book to introduce numerical methods such as
finite element analyses. The book Metal Forming Analysis by R. H. Wagoner and J. L.
Chenot (Cambridge University Press, 2001) covers the latest numerical techniques.
We feel that one should have a thorough understanding of a process before attempting
numerical techniques. It is vital to understand what constitutive relations are imbedded
in a program before using it. For example, the use of Hill’s 1948 anisotropic yield
criterion can lead to significant errors.
Joining techniques such as laser welding and friction welding are not covered.
I wish to acknowledge the membership in the North American Deep Drawing
Group from which I have learned much about sheet metal forming. Particular thanks
are given to Alejandro Graf of ALCAN, RobertWagoner of the Ohio State University,
John Duncan of the University of Auckland, Thomas Stoughton and David Meuleman
of General Motors, and Edmund Herman of Creative Concepts.