Jacketing of reinforced concrete columns is a common and useful strengthening method. This method substantially improves mechanical properties of the column, such as flexural strength as well as shear and ductility. In this paper, the behavior of confined reinforced concrete columns are investigated. The results indicate that the method is more effective for slender columns in the region of the...

During earthquake excitations, reinforced concrete bridge columns can be subjected to a combination of axial load, shear force, flexural moments, and torsional moments. The torsional moment can be much more significant in columns of bridges that are skewed, curved, have unequal spans, or unequal column heights. Combined loading including torsion can result in complex flexural and shear failure ...

The dynamic theory of deformable ellipsoidal inclusions in slow viscous flows was worked out by J.D. Eshelby in the 1950s, and further developed and applied by various authors. We describe three approaches to computing Eshelby’s ellipsoid dynamics and other homogeneous deformations. The most sophisticated of our methods uses differential-geometric techniques on Lie groups. This Lie group method...

This work considers the instability of the jet plume from an overexpanded, shockcontaining convergent-divergent nozzle and attempts to correlate this instability to internal shock-induced separation phenomena. Time resolved wall pressure measurements and Pitot measurements are used as primary diagnostics. For the conditions of this study flow separation is asymmetric resulting in a large separa...

One of the largest historical earthquakes in California occurred in 1872 along the Owens Valley fault located along the western margin of the Eastern California Shear Zone. New paleoseismic and optically stimulated luminescence data are the first to bracket the timing of the pre-1872 rupture to between 3.3 6 0.3 and 3.8 6 0.3 ka. These data yield an earthquake recurrence interval between 4100 a...

In this paper, a generalized expression for the flow field in axisymmetric extrusion process is suggested to be valid for any dies and the boundary shapes of the plastic deformation zone. The general power terms are derived and the extrusion force is calculated by applying upper bound technique for a streamlined die shape and exponential functions for shear boundaries. It is shown that assuming...

Recent observations show Heand N-enhancements in fast rotating O-type stars, while studies on shear mixing in rotating stars have shown that the μ-gradients generally inhibit mixing processes. However, these studies (including ours) ignored the other sources of turbulence, such as semiconvection and horizontal turbulence, which may be present in the medium and may modify the onset of shear mixi...

Fluids are inferred to play a major role in the deformation and recrystallization of many minerals (e.g. quartz, olivine, halite, feldspar). In this study, we sought to identify the effect of fluids on grain boundary morphology and recrystallization processes in marble mylonites during shear zone evolution. We compared the chemistry, microstructure and mesostructure of calcite marble mylonites ...

Article history: Received 26 December 2012 Received in revised form 14 August 2013 Accepted 5 October 2013 Available online 12 October 2013