In this paper, an upper bound approach is used to analyze the tube extrusion process through rotating conical dies with large mandrel radius. The material under deformation in the die and inside the container is divided to four deformation zones. A velocity field for each deformation zone is developed to evaluate the internal powers and the powers dissipated on all frictional and velocity disco...

Title of Thesis: ROCK FABRIC ANALYSIS OF THE SIERRA CREST SHEAR ZONE SYSTEM, CALIFORNIA: IMPLICATIONS FOR CRUSTAL-SCALE TRANSPRESSIONAL SHEAR ZONES Callan Bentley, Master of Science, 2004 Thesis Directed By: Dazhi Jiang, Assistant Professor, Geology Department Crustal-scale tabular shear zones are common features of transpressional orogens and arcs. Though foliation development in shear zones i...

We have conducted a study of toughening mechanisms in rubber modified polycarbonate systems in order to evaluate the sequence of deformation events which improve fracture toughness. We conclude that cavitation of the rubber particles occurs first, followed by massive shear yielding of the matrix material. The size and shape of the deformation zone created in front of the crack is governed by th...

[1] Coseismic deformation of the ground can be measured from aerial views taken before and after an earthquake. We chose the area of the Kickapoo-Landers step over along the 1992 Landers earthquake zone, using air photos (scale 1:40,000) scanned at 0.4 m resolution. Two photos acquired after the earthquake are used to assess the accuracy and to evaluate various sources of noise. Optical distort...

We used scaled experimental (analog) models with wet clay to investigate how conjugate sets of steeply dipping strike-slip faults affect deformation patterns during a subsequent phase of extension. In all twophase experiments, an initial phase of strike-slip deformation produces a long, wide deformation zone consisting of subvertical Riedel shears; synthetic R-shears and antithetic R'-shears tr...

[1] Problems associated with shear zone development in the lithosphere involve features of widely different time scales, since the gradual buildup of stress leads to rapid and localized shear instability. These phenomena have a large stiffness in time domain and cannot be solved efficiently by a single time-integration scheme. This conundrum has forced us to use an adaptive time-stepping scheme...

the massive sulphide deposit at kantienpan cu-zn mine is hosted by volcano sedimentary succession known as the areachap group, in the eastern part of namaqua metamorphic province, south africa. the deposits were affected by a complex deformation and metamorphic history and represent examples of upper amphibolite to granulite grade metamorphosed volcanic-hosted massive sulphide (vhms) depo...