Feasibility of glued laminated timber beams with tropical hardwoods

International audienceA feasibility study of glulam was carried out in French Guiana using local wood species. The aim was to determine gluing parameters affording satisfactory behaviour to manufactured glulam in a tropical climate. Three abundant wood species, with special properties, were selected for the study and Resorcinol-Phenol-Formaldehyde resin was used for bonding. Three industrial parameters were considered: adhesive spread rate, closed assembly time and gluing pressure. Delamination and shearing tests were carried outin accordance with European Standards. The tests revealed the influence of wood properties and manufacturing parameters on joint resistance. In fact, the results showed that specific gravity and the shrinkage coefficientgreatly influenced the gluing step. Indeed, wood with a medium specific gravity needed more adhesive and more pressure than wood with a high specific gravity. In addition, planning and lamella thicknesswere found to affect glue joint resistance

Surface Drilling Data for Constrained Hydraulic Fracturing and Fast Reservoir Simulation of Unconventional Wells

The objective is to present a new integrated workflow which leverages commonly available drilling data from multiple wells to build reservoir models to be used for designing and optimizing hydraulic fracture treatment and reservoir simulation. The use of surface drilling data provides valuable information along every wellbore. This information includes estimations of geomechanical logs, pore pressure, stresses, porosity and natural fractures. These rock properties may be used as a first approximation in a well-centric approach to geoengineer completions. Combining these logs from multiple wells into 3D reservoir models provides more value including using them in reservoir geomechanics, 3D planar hydraulic fracturing design and reservoir simulation. When using these 3D models and their results in a fast marching method simulator, the impact of the interference between wells can be estimated quickly while providing results like those derived with a classical reservoir simulator. Integrating surface drilling data with 3D reservoir models, hydraulic fracturing design and reservoir simulation into a single software platform results in a fast and constrained approach which allows for a more efficient management of unconventional wells

Hypoelastic, hyperelastic, discrete and semi-discrete approaches for textile composite reinforcement forming

International audienceThe clear multi-scale structure of composite textile reinforcements leads to develop continuous and discrete approaches for their forming simulations. In this paper two continuous modelling respectively based on a hypoelastic and hyperelastic constitutive model are presented. A discrete approach is also considered in which each yarn is modelled by shell finite elements and where the contact with friction and possible sliding between the yarns are taken into account. Finally the semi-discrete approach is presented in which the shell finite element interpolation involves continuity of the displacement field but where the internal virtual work is obtained as the sum of tension, in-plane shear and bending ones of all the woven unit cells within the element. The advantages and drawbacks of the different approaches are discussed

Approche hyperélastique pour la simulation des renforts fibreux en grandes transformations

Un modèle de comportement hyperélastique est proposé pour la simulation des renforts fibreux de composites en particulier tissés. Son objectif est de simuler à l\u27échelle macroscopique des opérations de mise en forme. Il représente une alternative aux approches continues hypoélastiques existantes. Un potentiel énergétique simple reproduisant les non linéarités matérielles connues des renforts tissés est proposé. Classiquement, les modes de déformations se caractérisent par des déformations faibles dans la direction des mèches et de grandes déformations de cisaillement plan. Le modèle est implémenté dans une routine utilisateur Vumat d\u27Abaqus/Explicit. La sensibilité de la solution à la densité de maillage et la pertinence des résultats ont été analysées pour différents tests de référence en grandes transformations : cisaillement pur et simple, cisaillement pur - extension. Enfin, le modèle est testé pour simuler une opération de formage par poinçon hémisphérique. Des résultats satisfaisants sont obtenus, notamment sur la prise en compte ou non de la rigidité associée au cisaillement plan entre les mèches

Approche hyperélastique pour la simulation des renforts fibreux en grandes transformations

Un modèle de comportement hyperélastique est proposé pour la simulation des renforts fibreux de composites en particulier tissés. Son objectif est de simuler à l échelle macroscopique des opérations de mise en forme. Il représente une alternative aux approches continues hypoélastiques existantes. Un potentiel énergétique simple reproduisant les non linéarités matérielles connues des renforts tissés est proposé. Classiquement, les modes de déformations se caractérisent par des déformations faibles dans la direction des mèches et de grandes déformations de cisaillement plan. Le modèle est implémenté dans une routine utilisateur Vumat d Abaqus/Explicit. La sensibilité de la solution à la densité de maillage et la pertinence des résultats ont été analysées pour différents tests de référence en grandes transformations : cisaillement pur et simple, cisaillement pur - extension. Enfin, le modèle est testé pour simuler une opération de formage par poinçon hémisphérique. Des résultats satisfaisants sont obtenus, notamment sur la prise en compte ou non de la rigidité associée au cisaillement plan entre les mèches.A hyperelastic model is proposed to simulate the fibre composites. Its objective is to simulate at the macroscopic level the forming operation. It represents an alternative to hypo-elastics continuous approaches. A simple energetic potential reproducing the non linearities known of woven is proposed. Classically, deformation modes are characterized by weak strains in the fibre direction and large plane shear strains. The model is implemented in routine user of Vumat of Abaqus/Explicit. The sensitivity of the solution to the number of elements and the relevancy of the results are analysed for different reference tests of large strain: picture frame test, simple shear test and simple shear -extension test. Finally, the model is tested to simulate the forming with hemispherical punch. Satisfactory results were obtained especially when taking or not in account the shear rigidity in the simulation.VILLEURBANNE-DOC'INSA LYON (692662301) / SudocSudocFranceF