Plane-Strain Slip-Line Fields for Metal-Deformation Processes

Abstract

BOOK REVIEWS a fluid-filled tube in which the tube can be elastic or viscoelastic but the fluid is assumed to be incompressible and inviscid. All articles are very mathematically and analytically oriented. Nevertheless, the articles cover a fairly wide range of wave propagation phenomena in viscoelastic media. In view of the fact that there are not many books available on viscoelasticity and even fewer on wave propagation in viscoelastic media, the appearance of this volume is welcome. It would serve as a useful reference for those who want to venture into this field.

Subfossil mammalian tracks (Flandrian) in the Severn Estuary, S. W. Britain: mechanics of formation, preservation and distribution

“…At large strains, some unglueing and slippage of the Plasticine prisms may be evident. Beneath the face of the punch is a narrow, roughly hemispherical zone of intense shear that bounds a ' dead ' region, as in the experiments of Johnson et al (1982) and Tapponnier et al (1982) (see figure 3 a). Upward displacement and vertical extension due to a much less intense radial compression is evident laterally from this zone and from the wall of the experimental shaft.…”

“…Along and just outward from the crest of the arch, however, circumferential tension exists compatible with a detectable radial compression and slight outward displacement of elements (figure 6 a-d ). Green (1951) and Johnson et al (1982) found upward and outward displacement in their experiments ; the simple doming experiments of Withjack & Scheiner (1982) and Marti et al (1994) produced radial fractures and a radial compression expressed internally and at the surface by outward micro-thrusts. Blocks that were deeply penetrated showed intense strain (e.g.…”

“…The conditions for steady yield and the deformation pattern at incipient yield vary with the shape of the indenter and a number of boundary conditions, as has been demonstrated for ideal plastics employing various theoretical techniques (Calladine 1969 ;Hill 1971 ;Johnson et al 1970Johnson et al , 1982, and recently, using rheologically more complex materials (Hill et al 1989 ;Hill 1992 ;Bower et al 1993). Two of these conditions are particularly important in the context of tracks in sediments : the extent of the elastic-plastic material in relation to the size of the punch, and whether or not the material adheres to the face of the punch.…”

“…When the face of the indenter is rough ( figure 3 a), the yield-point load for steady plastic deformation takes an upper bound of P l 2ka(1jπ\2), where P is the unit force and k is the yield strength, the slightly smaller lower bound being P l 5k (Prandtl 1920 ;Shield & Drucker 1953 ;Calladine 1969 ;Johnson et al 1982). Immediately beneath the indenter occurs a triangular ' dead ' region, BBC, in which the material simply moves downward with the punch, as in laboratory experiments illustrated by Johnson et al (1982) and Tapponnier et al (1982). In the adjoining regions ABCDA the material moves along the slip-lines sketched.…”

Metal forming and the finite-element method

“…5. For further reference, the books that provide a wealth of solutions to many metal-forming problems using the above methods are listed in the References [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”