A variational framework for the modeling of glassy polymers under finite strains

Continuum Mechanics and Thermodynamics - In this paper, a viscoelastic model able to capture important mechanical features of a wide class of glassy polymers is presented. Among them, the ability...     

A variational formulation for the incremental homogenization of elasto-plastic composites

This work addresses the micro–macro modeling of composites having elasto-plastic constituents. A new model is proposed to compute the effective stress–strain relation along arbitrary loading paths. The proposed model is based on an incremental variational principle (Ortiz, M., Stainier, L., 1999. The variational formulation of viscoplastic constitutive updates. Comput. Methods Appl. Mech. Eng. 171, 419–444) according to which the local stress–strain relation derives from a single incremental potential at each time step. The effective incremental potential of the composite is then estimated based on a linear comparison composite (LCC) with an effective behavior computed using available schemes in linear elasticity. Algorithmic elegance of the time-integration of J₂ elasto-plasticity is exploited in order to define the LCC. In particular, the elastic predictor strain is used explicitly. The method yields a homogenized yield criterion and radial return equation for each phase, as well as a homogenized plastic flow rule. The predictive capabilities of the proposed method are assessed against reference full-field finite element results for several particle-reinforced composites.     

Le globucid (n. d.) essais d' identité et dosages

This analytical study of Globucid (sulphanilaminoethylthiodiazole) comprises : l. The determination of physical constants, melting-point and solubilities, of the compound. 2. The identification of the different functional groups, arylamine, substituted benzene, sulphonamide and tests for aminoethylthiodiazole by colour and precipitation reactions, as well as a number of precipitation and microchemical reactions of Globucid itself. 3. A quantitative section : determination of total nitrogen and thiodiazole nitrogen by difference, determination of amino nitrogen, acidimetric and argentometric determination of the sulphonamide groups, determination of total sulphur and thiodiazole sulphur and finally bromometric assay of Globucid.     

Isopropylalkohol

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