La ética y el movimiento de Jesús

El autor se propone a mostraros cuál es la lectura ética que mejor define el Movimiento de Jesús: el dualismo tradicional de occidente que pone el énfasis en el deber ser, la recompensa externa y "el negocio divino" o el de una ética holística, igualitaria y liberadora, centrada en el descubrimiento de los propios auto-engaños, y de plena conciencia del ser. Desde un novedoso análisis ético, nos acerca a una lectura polémica de la ética subyacente en el Movimiento de Jesús

Cuando la utopía era ahora: una teorización sociológica holística sobre la autogestión libertaria

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Políticas y Sociología, Departamento de Sociología V (Teoría Sociológica), leída el 18-11-2015Depto. de Sociología: Metodología y TeoríaFac. de Ciencias Políticas y SociologíaTRUEunpu

Material models to study the Bauschinger effect on an aluminum shear test specimen

Sheet metal forming processes generally involve complex loadings and nonlinear material models. Combinations of drawing, re-drawing and/or reverse drawing operations commonly induce cyclic loads with non-proportional strain paths, leading to Bauschinger effects that can not be predicted by conventional isotropic hardening laws. In order to properly represent this effect, it is also required to accommodate an appropriate kinematic hardening model along with an anisotropic yield function. In this work, two different approaches will be used to predict the Bauschinger effect for an Aluminum shear test specimen: the rate dependent crystal plasticity model and a new combined isotropic/kinematic hardening model based on the two yield surfaces approach (loading and boundary yield surfaces)

Development of a one point quadrature shell element for nonlinear applications with contact and anisotropy

A general purpose shell element for nonlinear applications including sheet metal forming simulation is developed based on reduced integration with one point quadrature. The developed shell element has five degrees of freedom and four nodes. It covers flexible warping behavior without artificial warping correction. A physical stabilization scheme with the assumed natural strain method is employed to derive a strain field that can be decomposed into the sum of a constant and a linear term with respect to the natural coordinates. The rigid body projection is introduced to treat rigid body rotations effectively. The shell element incorporates elasto-plastic planar anisotropic material models based on the incremental deformation theory. Linear and nonlinear patch tests are performed and the results are compared with analytical or previously reported results. Simulations that include impact and deformable body contact are performed to show the robustness of the contact algorithm. Finally, to demonstrate the capability of handling anisotropic materials, the developed shell element is used for the circular cup drawing process simulation in order to predict the earing profile of Al 2008-T4 alloy sheet. © 2002 Elsevier Science B.V. All rights reserved

Unconstrained springback behavior of Al-Mg-Si sheets for different sitting times

In this work, the springback behavior of the commercial 6022 aluminum alloy in temper aging (T4) is investigated taking into account that the sheets, prior to deformation process, are initially pre-strained and then submitted to various sitting times at room temperature. The unconstrained cylindrical bending test based on the NUMISHEET2002 proceedings as presented by Yoon et al. [Yoon JW, Pourboghrat F, Chung K, Yang DY. Springback prediction for sheet metal forming process using a 3D hybrid membrane/shell method. International Journal of Mechanical Sciences 2002;44:2133-53] is selected as validation benchmark. For finite element simulations, the geometry is modeled by solid-shell finite elements using the formulation of Alves de Sousa et al. [Alves de Sousa RJ, Yoon JW, Cardoso RPR, Fontes Valente RA, Grácio JJ. On the use of a reduced enhanced solid-shell (RESS) element for sheet forming simulations. International Journal of Plasticity 2007;23:490-515; Alves de Sousa RJ, Cardoso RPR, Fontes Valente RA, Yoon J-W, Natal Jorge RM, Grácio JJ. A new one-point quadrature enhanced assumed strain (EAS) solid-shell element with multiple integration points along thickness: Part I - Geometrically linear applications. International Journal for Numerical Methods in Engineering 2005;62:952-77; Alves de Sousa RJ, Cardoso RPR, Fontes Valente RA, Yoon JW, Grácio JJ, Natal Jorge RM. A new one-point quadrature enhanced assumed strain (EAS) solid-shell element with multiple integration points along thickness: Part II - Nonlinear applications. International Journal for Numerical Methods in Engineering 2006;67:160-88]. The material behavior is described based on the work of Correia et al. [Correia JPM, Simões F, Gracio JJ, Barlat F, Ahzi S. A simple hardening rule accounting for time-dependent behavior in Al-Mg-Si alloys. Materials Science Engineering A 2007;456:170-9]. The results of conducted experiments and numerical simulations are compared. It can be concluded about the good agreement between experiments and simulations attesting the effectiveness of the material model utilized to describe the time-dependent hardening behavior. © 2008 Elsevier Ltd. All rights reserved

Development of a one point quadrature shell element for nonlinear applications with contact and anisotropy

A general purpose shell element for nonlinear applications including sheet metal forming simulation is developed based on reduced integration with one point quadrature. The developed shell element has five degrees of freedom and four nodes. It covers flexible warping behavior without artificial warping correction. A physical stabilization scheme with the assumed natural strain method is employed to derive a strain field that can be decomposed into the sum of a constant and a linear term with respect to the natural coordinates. The rigid body projection is introduced to treat rigid body rotations effectively. The shell element incorporates elasto-plastic planar anisotropic material models based on the incremental deformation theory. Linear and nonlinear patch tests are performed and the results are compared with analytical or previously reported results. Simulations that include impact and deformable body contact are performed to show the robustness of the contact algorithm. Finally, to demonstrate the capability of handling anisotropic materials, the developed shell element is used for the circular cup drawing process simulation in order to predict the earing profile of Al 2008-T4 alloy sheet

A nonlinear kinematic hardening model for the simulation of cyclic loading paths in anisotropic aluminum alloy sheets

Sheet metal forming processes generally involve complex loadings and material nonlinearities. Combinations of drawing, re-drawing and/or reverse drawing operations commonly induce cyclic loads with different strain paths, leading to Bauschinger effects that can not be predicted by conventional isotropic hardening laws. In order to properly represent such an effect, it is required to accommodate an appropriate kinematic hardening model along with a planar anisotropic yield function. Yld2000 (Barlat et al. [1]), for instance, can accurately capture both yield stress and r-value directionalities. In this work, the Barlat yield function Yld2000 is implemented with a nonlinear kinematic hardening model, based on the definition of two yield surfaces by Dafalias and Popov. The incremental deformation theory is used to properly handle the stress integration for non-quadratic ield functions in elastoplasticity

Development of a one point quadrature EAS solid-shell element

A correct reproduction of thickness effect can be accurately described by the use of three-dimensional solid elements. In addition to convenient formulation for constitutive law, solid element provides a straightforward extension to geometrically non-linear problems, particularly in the presence of large rotations, since only translational degrees of freedom are involved. Also, compared with shell elements, it is valid to consider double-sided contact because of real physical nodes on top and bottom surfaces without any further modification. However, for low order elements, as thickness/length ratio value tends to zero, the transverse shear-locking phenomenon becomes more evident. Also, plasticity leads to isochoric deformation, which is the main source of the volumetric locking phenomenon. Concerning bending dominant problems, it is difficult to use a single layer of solid elements due to the limitation of integration points along thickness direction. Multi-layered solid element increases the CPU time dramatically. In order to overcome these drawbacks, a new single layer solid-shell element is developed based on a one-point quadrature scheme, but allowing multiple integration points along thickness. A physical stabilization scheme, based on convective coordinate system, is used to control hourglass modes efficiently. To avoid thickness and volumetric locking behaviors, the formulation applies Simo and Rifai's Enhanced Assumed Strain method. The background theory for this element and numerical simulations for validation purposes are presented. Assessments show that the present formulation is efficient for linear and nonlinear shell applications