Existence and Uniqueness of Solutions in Nonassociated Mohr-coulomb Elastoplasticity:<strong/>

In 1902 Jacques Hadamard [1] formulated three conditions that mathematical models of physical phenomena should satisfy, namely that: (a) A solution exists (b) The solution is unique (c) The solution depends continuously on the problem data Problems involving models that satisfy all of these conditions are termed well-posed. Otherwise, if one or more conditions are violated, the problem is said to be ill-posed. The meaning of condition (a) is quite clear. Conditions (b) and (c) are often intimately linked and can for many practical purposes be coalesced into a single condition. In finite element analysis “non-unique ” solutions are often generated by altering the problem data slightly, for example through introduction of random imperfections. It is relatively well known (though not always appreciated to its full extent) that standard elastoplastic constitutive models may violate conditions (b) and (c) if the flow rule is not associated. Indeed, since the pioneering work of Rice [2], the ensuing ill

Quevedo y Proclo: lectura ontológica del soneto “Si quien ha de pintaros ha de veros”

Análisis de la influencia del neoplatonismo renacentista en el desarrollo de las convenciones anti-petrarquistas del Siglo de Oro tardío, plasmada en un soneto de Quevedo. La lectura muestra cómo el tropo procleano del «círculo de eros» da forma a la relación tópica del poeta con el objeto de su meditación, representada en esquemas retóricos y lenguaje derivados el discurso de la ontología neoplatónica. A study of the influence of Renaissance Neo-Platonism on the evolution of anti-Petrarchan conventions in the late Golden Age, as seen in a sonnet by Quevedo. The reading demonstrates how the Proclan trope of the «circle of eros» shapes the topical relationship between the poet and the object of his meditation, which is described in rhetorical structures and language derived from the discourse of Neo-Platonic ontology

An airblast hazard simulation engine for block caving sites

In this paper, a weakly compressible Lattice Boltzmann code is coupled with a realistic shape Discrete Element algorithm to create a simulation software to estimate the airspeed happening at airblast events in three dimensions. In an airblast event, air is compressed between falling rocks and the muckpile when the block caving method is used, creating potential hazardous air gusts compromising the safety of personnel and equipment. This work shows how the coupled code is capable of reproducing the key physical layers involved in this phenomenon such as the airspeeds attained by falling bodies in funnel geometries. After some validation examples, the code is used to evaluate the effect of the underground mine geometrical parameters on the potential airspeed. These examples show the potential of the software to be used by mining engineers to estimate accurately the impact of an airblast event

Homogenization and seismic assessment : review and recent trends

The mechanics of masonry structures has been for long underdeveloped in comparison with other fields of knowledge. Presently, non-linear analysis is a popular field in masonry research and advanced computer codes are available for researchers and practitioners. The chapter presents a discussion of masonry behaviour and clarifies how to obtain the non-linear data required by the computations. The chapter also addresses different homogenisation techniques available in the literature in the linear and rigid-plastic case, aiming at defining a catalogue and at discussing the advantages and disadvantages of the different approaches. Special attention is given to stress assumed models based either on a polynomial expansion of the micro-stress field or in the discretization of the unit cell by means of a few constant stress finite elements CST with joints reduced to interfaces. Finally, the aspects of seismic assessment are presented and case studies involving the use of macro-block analysis, static (pushover) analysis and time integration analysis are discussed.(undefined

Quevedo y Proclo: lectura ontológica del soneto “Si quien ha de pintaros ha de veros”

Análisis de la influencia del neoplatonismo renacentista en el desarrollo de las convenciones anti-petrarquistas del Siglo de Oro tardío, plasmada en un soneto de Quevedo. La lectura muestra cómo el tropo procleano del «círculo de eros» da forma a la relación tópica del poeta con el objeto de su meditación, representada en esquemas retóricos y lenguaje derivados el discurso de la ontología neoplatónica. A study of the influence of Renaissance Neo-Platonism on the evolution of anti-Petrarchan conventions in the late Golden Age, as seen in a sonnet by Quevedo. The reading demonstrates how the Proclan trope of the «circle of eros» shapes the topical relationship between the poet and the object of his meditation, which is described in rhetorical structures and language derived from the discourse of Neo-Platonic ontology

Numerical aspects of multi-ionic transport in elecrolytic solutions

A number of numerical solution procedures for the Poisson-Nernst Planck equations are explored. In the presentation numerical examples illustrating the advantages and disadvantages of the carious strategies will be discussed