Avascular necrosis of the head of the femur is found in many different conditions. Most often it occurs after injury or during growth. It has been generally accepted that vascular occlusion is its immediate cause (Trueta and Harrison 1953, Trueta 1957). This occlusion leads primarily to ischaemia of the tissues, which results in necrosis if the circulation is not restored in time. Morphological...

We investigate shock response of single crystal and nanocrystalline pentaerythritol tetranitrate (PETN) with a coarse-grained model and molecular dynamics simulations, as regards mechanical hotspot formation in the absence or presence of grain boundaries (GBs). Single crystals with different orientations, and columnar nanocrystalline PETN with regular hexagonal, irregular hexagonal, and random ...

Progressive collapse is a situation where local failure of a primary structural component leads to the collapse of adjoining members which, in turn, leads to additional collapse. Hence, the total damage is disproportionate to the original cause. The most common local failure in framed structure is assumed to be column failure. In this paper, a new approach for dynamic column removal in framed s...

In this paper, a novel approach is proposed to investigate the progressive collapse damage of prismatic thin walled metal columns with different regular cross sections, under the action of axial quasi-static and impact loads. The present work mainly focuses on implementation of some important factors which have been neglected in other studies. These factors include the effect of reducing impact...

Considering the vulnerability of double-layer grid space structures to progressive collapse phenomenon, it is necessary to pay special attention to this phenomenon in the design process. Alternate path method is one of the most appropriate and accepted methods for progressive collapse resistant design of structures. Alternate Path Method permits local failure to occur but provides alternate pat...

Abstract Volcano flank collapses have been documented at ocean islands worldwide and are capable of triggering devastating tsunamis, but little is known about the precursory processes deformation changes prior to failure. This makes 22 December 2018 collapse Anak Krakatau in Indonesia a key event geosciences. Here, we provide direct insight into final collapse. We analyzed interferometric synth...

Magnetosome chains produced by magnetotactic bacteria are important paleoenvironmental and paleomagnetic recorders. It has been shown that magnetic properties of magnetosome closely related to their morphology chain structures; however, the in situ structures sediments (magnetofossils) not known. subject various deformations after cell dissolution therefore unlikely be fully intact, obscuring o...

This paper presents a simplified approximate analysis of the overall collapse of the towers of World Trade Center in New York on September 11, 2001. The analysis shows that if prolonged heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. DOI: 10.1061/~ASCE!0733-9399~2002!128:1~2! CE Database keywords: New York; New York City...

The response of moment resisting frame structures to seismic excitation is strongly dependent on the ability of particular structural members to sustain relatively large inelastic deformations without significant degradation of lateral and axial load-carrying capacity. Conventional reinforced concrete frame structures are typically designed according to the strong column/weak beam concept, whic...

Abstract Understanding the mechanisms of strain localization leading to brittle failure in reservoir rocks can shed light on geomechanical processes such as porosity and permeability evolution during rock deformation, induced seismicity, fracturing, subsidence geological reservoirs. We perform triaxial compression tests three types porous reveal local deformation that control system-size failur...