Hardening effects on formability limit prediction based on gurson-type damage models and bifurcation analysis

In this work, ductility limits of metallic materials, associated with the occurrence of strain localization, are predicted using the GTN damage model coupled with bifurcation theory. The resulting approach is implemented into the finite element code ABAQUS within the framework of large plastic strains and a fully three-dimensional formulation. A parametric study with respect to damage and hardening parameters is conducted in order to identify the most influential material parameters on strain localization. The analysis shows that the damage parameters have a significant impact on the predicted ductility limits, while the effect of hardening parameters on strain localization depends on the choice of void nucleation mechanism

Communication framework to support more effective onsite construction monitoring

The UK construction industry has recently witnessed an increasing demand for cost-reduction strategies due to the strict government regulations on BIM implementation. This adoption will certainly lead to a continuous work improvement, better project delivery and communication. Although the UK government has set a target of 15–20% saving on the costs of capital projects by the full implementation of BIM level 2 in 2016, this figure is unlikely to be met since the majority of construction companies are still spending approximately £20 billion per year on rebuilding and repairing the construction defects caused by miscommunication. This research addresses the problem of communication using traditional methods (i.e. communication through paper-based documents and drawings) and its impact during the construction phase in relation to clash detection. Next, we will present a communication framework using advanced visualisation technique such as augmen ted reality (AR) combined with a BIM model with an easy access to the IFC f ile on site for a compliance checking between the BIM model and the actual co nstruction site. Subsequently, site inspection can be performed more efficiently, and with more reliability. Furthermore, early warning on future occu rring clashes can be given. To reach our objectives, the research has been designed using real case scenario, following two phases of implementation. The first phase include the communication study and consists of determining users requiring a ssistance with regard to site monitoring and inspection, whereas the second, built on the results of the first phase to specify and implement the mobile AR syste

Application of the continuum shell finite element SHB8PS to sheet forming simulation using an extended large strain anisotropic elastic–plastic formulation

http://link.springer.com/article/10.1007%2Fs00419-012-0620-xThis paper proposes an extension of the SHB8PS solid–shell finite element to large strain anisotropic elasto-plasticity, with application to several non-linear benchmark tests including sheet metal forming simulations. This hexahedral linear element has an arbitrary number of integration points distributed along a single line, defining the "thickness" direction; and to control the hourglass modes inherent to this reduced integration, a physical stabilization technique is used. In addition, the assumed strain method is adopted for the elimination of locking. The implementation of the element in Abaqus/Standard via the UEL user subroutine has been assessed through a variety of benchmark problems involving geometric non-linearities, anisotropic plasticity, large deformation and contact. Initially designed for the efficient simulation of elastic–plastic thin structures, the SHB8PS exhibits interesting potentialities for sheet metal forming applications – both in terms of efficiency and accuracy. The element shows good performance on the selected tests, including springback and earing predictions for Numisheet benchmark problems

Framing digital tools and techniques in built heritage 3D modelling: the problem of level of detail in a simplified environment

Recently, the built heritage sector has witnessed an increase demand for 3D models of historical sites mainly due to the widespread of new technologies in buildings’ surveying. Although these technologies have been credited for enabling highly detailed 3D modelling of the built heritage, their implementation is still so complex and costly. This research aims to explore the possibility of implementing new low-cost digital acquisition technologies and modelling techniques as an alternative to the existing expensive ones in terms of level of detail (LOD), as an attempt to enable low-skilled users in simplified environment, which are faced paced leaning milieus in education, places with high constraints, or developing countries, to practically learn about their built heritage; consequently, contribute to its preservation. To achieve this purpose, the most diffused SFM and laser scanning open-source packages were first cross-compared using web-content analysis data collection method. Afterwards, the best programme from each category namely; Autodesk 123D catch and Reconstructme, accompanied with Canon D550 camera and Xbox Kinect, respectively, were intensively evaluated through an experiment. The analysis of the findings has suggested that low-cost close-range photogrammetry can replace laser scanning when there is a lack of funding and time

Impact of household transitions on domestic energy consumption and its applicability to urban energy planning

The household sector consumes roughly 30% of Earth’s energy resources and emits approximately 17% of its carbon dioxide. As such, developing appropriate policies to reduce the CO2 emissions, which are associated with the world’s rapidly growing urban population, is a high priority. This, in turn, will enable the creation of cities that respect the natural environment and the well-being of future generations. However, most of the existing expertise focuses on enhancing the thermal quality of buildings through building physics while few studies address the social and behavioral aspects. In fact, focusing on these aspects should be more prominent, as they cause between 4% and 30% of variation in domestic energy consumption. Premised on that, the aim of this study was to investigate the effect in the context of the UK of household transitions on household energy consumption patterns. To achieve this, we applied statistical procedures (e.g., logistic regression) to official panel survey data comprising more than 5500 households in the UK tracked annually over the course of 18 years. This helped in predicting future transition patterns for different household types for the next 10 to 15 years. Furthermore, it enabled us to study the relationship between the predicted patterns and the household energy usage for both gas and electricity. The findings indicate that the life cycle transitions of a household significantly influence its domestic energy usage. However, this effect is mostly positive in direction and weak in magnitude. Finally, we present our developed urban energy model “EvoEnergy” to demonstrate the importance of incorporating such a concept in energy forecasting for effective sustainable energy decision-making

Profil épidémiologique des fibromes utérins dans la région de Sidi Bel Abbes, Algérie

Introduction: Les léiomyomes ou fibromyomes plus communément dénommés fibromes, sont les tumeurs les plus répandues du tractus génital féminin. Ils affectent 20 à 25% des femmes en activité génitale. Notre étude vise à élucider la réalité de ce type de pathologie dans la région de sidi bel Abbes, nord-ouest d'Algérie. Méthodes: A travers une étude rétrospective allant du 1er janvier 2008 au 1 mai 2011 portant sur les patientes opérées pour fibrome au sein de la maternité de Sidi Bel Abbes, nous avons relevé les particularités épidémiologiques et cliniques de cette pathologie. Résultats: Au total 323 cas de fibromes ont été recensés. La tranche d'âge la plus touchée varie de 40 à 44 ans dans une fourchette d'âge comprise entre 20 et 74 ans. 37.83% des patientes étaient nullipares. Une prédominance des patientes dont l'âge de la ménarche est précoce, a été retenue (60.3%). 3% des femmes ont présenté un terrain familial prédisposant. La symptomatologie était dominée par les hémorragies génitales (35%). La majorité des patientes (51.70%) présentait un utérus polymyomateux dont la localisation des fibromes était principalement corporéale (96%), sous séreuse (43%). Le traitement était conservateur dans 71.82% des cas. Conclusion: Sur la base des résultats obtenus, la mise au point d'un programme national de sensibilisation et de dépistage précoce, s'imposeKey words: Fibromes, étude rétrospective, particularités épidémiologiques, Sidi Bel Abbes

MODELISATION DE SYSTEMES DE PRODUCTION ORIENTES SERVICES

International audienceCet article traite de la problématique de la servicisation : transition de modèle d'entreprise depuis un modèle d'entreprise de production de bien, vers un modèle basé sur la production couplée de biens et de services. Après avoir situé les enjeux de cette transformation économique et organisationnelle, nous proposons une démarche de modélisation des systèmes de production orientés services, puis nous approfondissons la modélisation d'un sous-système spécifique : le système d'usage. Nous présentons un modèle conceptuel du système d'usage, puis une application industrielle mettant en évidence une implémentation de ce modèle, destinée à une étude par simulation

A smart urban energy prediction system to support energy planning in the residential sector

The UK residential sector accounts for approximately 27%., and 17% of the country energy consumption and its CO2 emission, respectively. Thus, developing appropriate polices to reduce the environmental factors, which are associated with the CO2 emissions of a rapidly growing urban population, constitutes a high priority. Moreover, ensures the creation of cities that respect the natural environment and the well-being of future generations. While a great deal of expertise on detailing and constructing low-energy buildings and cities has been developed, it is fragmented and does not consider the concept of household life-cycle demographic transitions in the prediction of residential energy consumption. This research aimed to develop an integrated 3D urban energy prediction tool which supports decision-making for a sustainable energy monitoring and planning in the residential sector. This, while considering the CK household demographic transition patterns in the energy prediction process. To attain the above aim, the research embraced a mixed-methods methodology with 4 stages of practical implementations. In stages 1 and 2, statistical procedures such as binary logistic regression, were applied to the British household panel data survey (BHPS) to attain the two following objectives. First, to analyse the socio-economic and demographic factors affecting the UK household transitions; consequently, predict future transition patterns in the next 10-15 years. Secondly, to investigate the impact of the predicted transition patterns on the residential energy consumption. The examination of the findings indicated that the nature of independent factors and their degree of influence on household transition patterns were not consistent across the 10-15 years. Moreover, it advised that household transitions mostly have a positive but weak effect on their energy usage. Based on those findings, a linear regression model was developed to predict the households' future electricity usage in function of their transition, demographic and socio­ economic variables. In phases 3 and 4, a 3D urban energy prediction tool (EvoEnergy) was developed by first building a 3D semantic model of a pilot area in Nottingham city. Moreover, by integrating the research findings from stages 1 and 2 into EvoEnergy using computer scripting, open-source game technology, and 3D visualisation techniques. Finally, despite the facts that the benchmarking of EvoEnergy highlighted some areas for improvement, it has advised that EvoEnergy has the ability to predict domestic electricity consumption at the building and neighbourhood levels with a good accuracy(+/- 5% error)

EXODuS: Exploratory OLAP over Document Stores

OLAP has been extensively used for a couple of decades as a data analysis approach to support decision making on enterprise structured data. Now, with the wide diffusion of NoSQL databases holding semi-structured data, there is a growing need for enabling OLAP on document stores as well, to allow non-expert users to get new insights and make better decisions. Unfortunately, due to their schemaless nature, document stores are hardly accessible via direct OLAP querying. In this paper we propose EXODuS, an interactive, schema-on-read approach to enable OLAP querying of document stores in the context of self-service BI and exploratory OLAP. To discover multidimensional hierarchies in document stores we adopt a data-driven approach based on the mining of approximate functional dependencies; to ensure good performances, we incrementally build local portions of hierarchies for the levels involved in the current user query. Users execute an analysis session by expressing well-formed multidimensional queries related by OLAP operations; these queries are then translated into the native query language of MongoDB, one of the most popular document-based DBMS. An experimental evaluation on real-world datasets shows the efficiency of our approach and its compatibility with a real-time setting