22 research outputs found
The Palmetto State song
An illustrated cover for sheet music celebrating the South Carolina state convention on December 20, 1860, where an ordinance of secession was passed unanimously, thereby severing the state's ties with the Union. The song is "respectfully dedicated to the signers of the Ordinance of Secession." The cover illustration shows the interior of the crowded hall, where on a stage several of the 169 delegates are gathered around the secession document. Above them hangs the flag of South Carolina, with a palmetto appearing under an arch. Above the arch is an allegorical mural with a palmetto tree in the center, under which Music (or Poetry, holding a lyre), Liberty, and a third female figure repose. The central vignette is flanked by a farmer (left) and sailor with an anchor. Two additional allegorical figures appear in niches on either side of the stage.A. Grunevald del.Lith. by August Hoen & Co. Baltimore.Title appears as it is written on the item."The Confederate Image," p. 10-11.Published in: American political prints, 1766-1876 / Bernard F. Reilly. Boston : G.K. Hall, 1991, entry 1861-2
Conception NumĂ©rique dâun Ă©valuateur technologique de grande dimension en composite pour la rĂ©paration collĂ©e
National audienceLa conception dâun Ă©valuateur technologique dâĂ©tude dâinterface collĂ©e typique dâune rĂ©paration structurale est prĂ©sentĂ©e.. Ce papier se concentre prĂ©sente une stratĂ©gie de modĂ©lisation lĂ©gĂšre en temps de calcul adaptĂ©e Ă une interface de rĂ©paration en step-lap ouvrant la voie Ă une conception dâun Ă©valuateur Ă partir dâune stratĂ©gie dâoptimisation nĂ©cessitant un grand nombre dâitĂ©rations.. Le cahier des charges auquel doit rĂ©pondre cet Ă©valuateur ainsi que la modĂ©lisation initiale retenue sont prĂ©sentĂ©es en dĂ©tail. Ces travaux doivent permettre de lancer des centaines dâitĂ©rations lors de la procĂ©dure dâoptimisation afin de trouver la cinĂ©matique de chargement idĂ©ale de la piĂšce menant au dĂ©collement du patch de rĂ©paration dans la zone dĂ©sirĂ©e et sous lâĂ©tat de contrainte dĂ©sirĂ©
Vers une méthodologie robuste pour la réparation de piÚces composites primaires aéronautiques
International audienceCe papier prĂ©sente une mĂ©thodologie permettant dâĂ©tudier les problĂšmes associĂ©s Ă la rĂ©paration « sur site » des structures primaires principales en matĂ©riaux composites. Si cette derniĂšre devient obligatoire, cela entraine une immobilisation onĂ©reuse. La recherche dâune solution Ă un endommagement structural est un problĂšme au cas par cas, qui relĂšve des Ă©tapes suivantes : la conception dâun patch, lâanalyse des contraintes, lâenlĂšvement de la matiĂšre endommagĂ©e, la construction du patch, lâassemblage et les finitions. De plus, la solution composite doit ĂȘtre considĂ©rĂ©e avec ses diffĂ©rentes variabilitĂ©s sans oublier le lien Ă©troit entre les diffĂ©rentes Ă©chelles (de lâĂ©chelle microscopique Ă lâĂ©chelle de la structure). Pour aborder de telles questions, un Evaluateur Technologique Multi-InstrumentĂ© (ETMI) a Ă©tĂ© dĂ©veloppĂ© afin de reproduire les conditions de travail reprĂ©sentatives des zones de rĂ©paration dans les structures industrielles. Câest une sorte de boite Ă outils dans laquelle figure un banc dâessais multi axiaux modulaire. Des chargements multi axiaux sont identifiĂ©s afin de placer la zone rĂ©parĂ©e dans un champ de contraintes choisi Ă lâavance. Les rĂ©sultats sont discutĂ©s Ă travers la corrĂ©lation entre donnĂ©es expĂ©rimentales et rĂ©sultats issus de modĂšles numĂ©riques pour diffĂ©rents types dâĂ©valuateur
TOWARD A MULTI-LEVEL EVALUATION OF BONDED REPAIRS FOR COMPOSITE ASSEMBLY: SHEAR CHARACTERIZATION
International audienceAn innovative bonded repair evaluation, through the design of a detail-sized evaluator and representative from the industrial application, is proposed thanks to the study of the interface behaviour. This paper deals with a primary major phase which is necessary to get âelementaryâ, uncoupled and local information. This work is done following three stages: First, a 3D numerical model has been designed to address an adequate geometry for the coupons. Secondly, non-standard shear tests (due to non-standard geometry) have been conducted. Some geometrical data have been measured. Finally, using the results of this geometrical evaluation, a 2D numerical modelling strategy, has been developed to be as light as possible and compared to experimental results The low-time consuming numerical model will be helpful for the future numerical design of the bonded repair evaluator
Vers une méthodologie robuste pour la réparation de piÚces composites primaires aéronautiques
International audienceCe papier prĂ©sente une mĂ©thodologie permettant dâĂ©tudier les problĂšmes associĂ©s Ă la rĂ©paration « sur site » des structures primaires principales en matĂ©riaux composites. Si cette derniĂšre devient obligatoire, cela entraine une immobilisation onĂ©reuse. La recherche dâune solution Ă un endommagement structural est un problĂšme au cas par cas, qui relĂšve des Ă©tapes suivantes : la conception dâun patch, lâanalyse des contraintes, lâenlĂšvement de la matiĂšre endommagĂ©e, la construction du patch, lâassemblage et les finitions. De plus, la solution composite doit ĂȘtre considĂ©rĂ©e avec ses diffĂ©rentes variabilitĂ©s sans oublier le lien Ă©troit entre les diffĂ©rentes Ă©chelles (de lâĂ©chelle microscopique Ă lâĂ©chelle de la structure). Pour aborder de telles questions, un Evaluateur Technologique Multi-InstrumentĂ© (ETMI) a Ă©tĂ© dĂ©veloppĂ© afin de reproduire les conditions de travail reprĂ©sentatives des zones de rĂ©paration dans les structures industrielles. Câest une sorte de boite Ă outils dans laquelle figure un banc dâessais multi axiaux modulaire. Des chargements multi axiaux sont identifiĂ©s afin de placer la zone rĂ©parĂ©e dans un champ de contraintes choisi Ă lâavance. Les rĂ©sultats sont discutĂ©s Ă travers la corrĂ©lation entre donnĂ©es expĂ©rimentales et rĂ©sultats issus de modĂšles numĂ©riques pour diffĂ©rents types dâĂ©valuateur
Toward a numerical conception of a technological evaluator for composite structural repair: shear characterization
International audienceno abstrac
Conception NumĂ©rique dâun Ă©valuateur technologique de grande dimension en composite pour la rĂ©paration collĂ©e
National audienceLa conception dâun Ă©valuateur technologique dâĂ©tude dâinterface collĂ©e typique dâune rĂ©paration structurale est prĂ©sentĂ©e.. Ce papier se concentre prĂ©sente une stratĂ©gie de modĂ©lisation lĂ©gĂšre en temps de calcul adaptĂ©e Ă une interface de rĂ©paration en step-lap ouvrant la voie Ă une conception dâun Ă©valuateur Ă partir dâune stratĂ©gie dâoptimisation nĂ©cessitant un grand nombre dâitĂ©rations.. Le cahier des charges auquel doit rĂ©pondre cet Ă©valuateur ainsi que la modĂ©lisation initiale retenue sont prĂ©sentĂ©es en dĂ©tail. Ces travaux doivent permettre de lancer des centaines dâitĂ©rations lors de la procĂ©dure dâoptimisation afin de trouver la cinĂ©matique de chargement idĂ©ale de la piĂšce menant au dĂ©collement du patch de rĂ©paration dans la zone dĂ©sirĂ©e et sous lâĂ©tat de contrainte dĂ©sirĂ©
Added value of technological evaluators for structural repair characterization: MITE Toolbox
International audienceThis paper introduces a methodology to solve open issues associated to âon fieldâ repair of primary principal structures for composites. If a repair is mandatory, it leads to a costly immobilization. Structural damage needs a case by case solution including design, stress analysis, damaged zone removal, patch construction, set-up and finishing. Furthermore composite solution needs to be considered with its real industrial variabilities and with a continuous link between all scales (from micro scale to structure scale). To address such challenges, Multi-Instrumented Technological Evaluator Toolbox (MITE Toolbox) is developed in order to reproduce the representative working conditions of repair areas in industrial structures. Thanks to a multi-axial modular test device, multi-axial loadings are chosen for placing the repair zone under a chosen representative strain fields. Results are discussed through comparison between experimental data and FE models results for several Multi-Instrumented Technological Evaluator types
Multiscale numerical analysis of trm-reinforced masonry under diagonal compression tests
The present paper reports an experimental study coupled with a numerical modelling approach to simulate masonry walls strengthened with textile-reinforced mortar (TRM). This innovative reinforcing technique is based on high-strength fibre grids embedded into inorganic matrices, and it has recently been promoted for the seismic retrofitting of historical masonry buildings. In the experimental campaign presented here, two different commercial TRM systems are applied to single-leaf clay masonry panels. The specimens are then subjected to diagonal compression tests in order to evaluate the effects of TRM on the structural performance. The proposed finite element (FE) model, based on an original multiscale approach, is employed to simulate the diagonal compression tests. The numerical results show a very good agreement with the experimental data, including in terms of failure mode. In particular, the approach reproduces the macroscopic behaviour of the masonry panels as regards the force-displacement response, and it allows for the possibility of simulating bed joint sliding and TRM layer debonding
Compressive behaviour of concrete elements confined with GFRP-prefabricated bonded shells
International audienceIn this paper, a new technique is proposed to confine concrete columns using GFRP-prefabricated bonded shells and a shrinkage-compensating cement mortar. The confinement is performed with three identical shells, each of which contains two stepped lap joints at their ends. The main advantage of this technique is that the shells can be directly assembled on site by structural bonding to cover any column shape. The gap between the shells and the column is filled with shrinkage-compensating cement mortar. To evaluate the efficiency of this technique, several concrete specimens were confined, instrumented and tested under monotonic compression. To simulate the actual strengthening conditions, the load was directly applied on the concrete cross-section. The results show clearly the benefits of an efficient confinement in terms of a noticeable increase in the axial strength and ductility where the stress\textendashstrain curves are characterised by a third softening phase and the failure mode which spread over the whole length of the shells