Shear

Fractal measurements using the Cantor's dust method in a linear one-dimensional analysis mode were made on the fracture patterns revealed on two-dimensional, planar surfaces in four granites. This method allows one to conclude that: (1) The fracture systems seen on two-dimensional surfaces in granites are consistent with the part of fractal theory that predicts a repetition of patterns on different scales of observation, self similarity. Fractal analysis gives essentially the same values of D on the scale of kilometres, metres and centimetres (five orders of magnitude) using mapped, surface fracture patterns in a Sierra Nevada granite batholith (Mt. Abbot quadrangle, Calif.). (2) Fractures show the same fractal values at different depths in a given batholith. Mapped fractures (main stage ore veins) at three mining levels (over a 700 m depth interval) of the Boulder batholith, Butte, Mont. show the same fractal values although the fracture disposition appears to be different at different levels. (3) Different sets of fracture planes in a granite batholith, Central France, and in experimental deformation can have different fractal values. In these examples shear and tension modes have the same fractal values while compressional fractures follow a different fractal mode of failure. The composite fracture patterns are also fractal but with a different, median, fractal value compared to the individual values for the fracture plane sets. These observations indicate that the fractal method can possibly be used to distinguish fractures of different origins in a complex system. It is concluded that granites fracture in a fractal manner which can be followed at many scales. It appears that fracture planes of different origins can be characterized using linear fractal analysis.

Torsion extrusion (TE) process was performed successfully for consolidation of commercially pure aluminum powder at 350 °C. It was shown by a specific mechanism that the shear strains applied during consolidation of aluminum powder by the TE process have a considerable effect on the micro-structural shape of the porosities and also their omission efficiency. Density measurements showed that in the TE process a better consolidation, with respect to hot forward extrusion, was accomplished. Tensile and hardness tests results showed superior values for the ultimate tensile strength (UTS) and hardness values in the specimens produced by the TE process.

The effect of binder properties on torque curves, granule growth kinetics, wet mass consistency and dry granule strength has been investigated in this study. Granulation runs have been performed on a fine cohesive microcrystalline cellulose powder (Avicel 105, d50=20μm) in two types of laboratory high shear mixers: a Mi-Pro high shear mixer using a 1.9L bowl and a 6L Diosna

A series of experiments were performed to further investigate the phenomenon of shear-banding in surfactant solutions. Many surfactant solutions, through their unique amphiphilic chemistry, form long wormlike micelle structures which behave like living polymers. These wormlike micelles have interesting viscoelastic properties and have been the subject of a number of recent studies. These water-based surfactant systems are widely used in

Abstract. Precast concrete construction with prestressed precast hollow core slab as floor and roofing is being extensively used in the Gulf region. These one way slabs are sometimes subjected to unforeseen loads with a partition wall in shear zone or as a cantilever. A detailed experimental program involving full-scale load testing of hollow core slabs has been conducted involving testing of virgin and CFRP strengthened slabs in flexure and shear. This paper presents the results of the experimental and numerical evaluation of flexural and shear behavior of the hollow core slabs. The hollow-core slabs were modeled using the nonlinear finite element software DIANA and the load deflection behavior and ultimate capacity were evaluated numerically. For the FE model, concrete was modeled using Drucker-Prager with tension cut-off failure criterion, and Von-Mises plasticity with multilinear isotropic hardening was used to model the prestressing strands. Comparison between the experimental ...

Using the analytical approaches developed, the cross section of the new fibre composite beam described in the prequels to this paper is designed in order to avert secondary failure modes. A series of specimens have been built and put through a thorough testing regime to establish the performance of the beam. To gain confidence in the analytical models and achieve further understanding of the beam behaviour, a rigorous nonlinear finite element analysis is also presented. It was found that the analytical model agreed relatively well with the experiment and the FE analysis, thus validating the underlying assumptions.

A truss model is presented in this paper to predict the load–deflection response of reinforced concrete beams subjected to flexure and shear. The truss model which has struts at various angles is derived considering concrete contribution. The concrete contribution is then integrated ...

Published accounts of peat mass movements throughout the last 500 years reveal common characteristics among the failures; however, there has been no consistency in the terminology used to describe them. Given the apparently increasing frequency of peat failures in the British Isles and the possibility of more peat failures elsewhere in the world as a consequence of climate change, there is a need for a specific classification scheme. This paper proposes a scheme that uses clearly defined terms that can be readily applied and reliably used to understand and assess future hazards from peat mass movements. The paper begins with a general definition of what should constitute a ‘peat failure’, then presents a precisely defined classification scheme for peat landslides (i.e. excluding creep), using type of peat deposit and failure morphology as the key criteria. The new scheme for peat failures is discussed in the context of existing landslide classification systems. Definitions are provided for bog bursts (flow failure of raised bogs), bogflows (flow failure of blanket bogs), bog slides (shear failure and sliding of blanket bogs), peat slides (shear failure at peat–mineral interface in blanket bogs), peaty-debris slides (shear failure within mineral substrate beneath blanket bogs) and peat flows (natural failures of other types of peat deposits including flow failure caused by head-loading). Some practical problems of classifying peat failures are discussed.