An elliptic integral solution for the post-buckling response of a linear-el
astic and hygrothermal beam fully restrained against axial expansion is pre
sented. Whereas in the classical solutions the extension of the beam can be
neglected, a well-posed formulation of the title problem must include the
extension. The solution for the limiting case of a string is presented. The
present solution shows that the magnitude of the compressive axial load is
a maximum at the onset of buckling and decreases as the potential for free
expansion is increased; this is in contrast to the approximate solutions f
ound in the literature. (C) 1999 Elsevier Science Ltd. All rights reserved.