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Escola Superior de Tecnologia e Gestão (ESTG) >
Artigos em Acta de Conferência Internacional (ESTG) >
Utilize este identificador para referenciar este registo:
http://hdl.handle.net/10314/3375
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| Título: | Towards the Accurate Modeling of Amorphous Non-Linear Materials - Polymer Stress Relaxation (I) |
| Autores: | Cruz Pinto, José
André, José Reinas |
| Palavras Chave: | Polymer
Stress Relaxation |
| Data: | 1-Mar-2016 |
| Editora: | Wiley Online Library - Polymer Engineering & Science |
| Resumo: | We expand our recently published analytical modeling strategy for polymer non-linear stress relaxation (A) to specify the remaining steps to more accurately deal with the non-affine nature of the materials’ local strains and stresses relative to their average overall counterparts, and (B) to make it consistent with a new general cooperative theory of materials dynamics. The models (1) describe a non linear (strain-dependent) behavior that only becomes linear at very low strains, (2) account for the effect of reduced differences between the initial and final plateau modulus, of importance in semi-crystalline polymers, (3) quantify the effect of temperature, (4) may quantify the effects of changes in free volume, and (5) ensure very fast computations of the materials’ response irrespective of the experimental time scale. The models are sensitive to the influence of different initial states of the material, as may result from varying degrees of molecular orientation and aging levels, and are able to predict from experimentally measured stress relaxation moduli (for a poly (methylmethacrylate – PMMA) and a bis-phenol-A polycarbonate – PC) the values of such meaningful physical properties as the crossover frequency, νc, and temperature, Tc, in agreement with independently measured values, the initial and long-time plateau moduli, and the minimum activation energy. |
| URI: | http://hdl.handle.net/10314/3375 |
| ISSN: | doi/10.1002/pen.24260 |
| Aparece nas Colecções: | Artigos em Acta de Conferência Internacional (ESTG)
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Ficheiros deste Registo:
| Ficheiro |
Descrição |
Tamanho | Formato |
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| Final Stress Relaxation I_pg1.pdf | | 36Kb | Adobe PDF | Ver/Abrir | |
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