Historically, a major problem for the study of the large deformation of
crystalline solids has been the apparent lack of unity in experimentally
determined stress-strain functions. The writer's discovery in 1949 of
the unexpectedly high velocity of incremental loading waves in
pre-stressed large deformation fields emphasized to him the pressing
need for the independent, systematic experimental study of the subject,
to provide a firm foundation upon which physically plausible theories
for the finite deformation of crystalline solids could be constructed.
Such a study undertaken by the writer at that time and continued
uninterruptedly to the present, led in 1956 to the development of the
diffraction grating experiment which permitted, for the first time, the
optically accurate determination of the strain-time detail of non-linear
finite amplitude wave fronts propagating into crystalline solids whose
prior history was precisely known. These experimental diffraction
grating studies during the past decade have led to the discovery that
the uniaxial stress-strain functions of 27 crystalline solids are
unified in a single, generalized stress-strain function which is
described, much of it hitherto unpublished, in the present monograph.
The detailed study of over 2,000 polycrystal and single crystal uni-
axial stress experiments in 27 crystalline solids, in terms of the
variation of a large number of pertinent parameters, has provided new
unified pat- terns of understanding which, it is hoped, will be of
interest and value to theorists and experimentalists alike.