Yazar "Drozdov, A.D." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Cyclic viscoplasticity of semicrystalline polymers with finite strains: observations and constitutive modeling
    (World Scientific Publishing Co. Pte Ltd, 2012) Drozdov, A.D.; Düşünceli, Necmi; Klitkou, R.; Christiansen, J. Dec.
    Observations are reported on low density polyethylene and isotactic polypropylene in uniaxial tensile cyclic tests (oscillations between maximum elongation ratios kmax and the zero minimum stress σmin with kmax increasing monotonically with number of cycles). Constitutive equations are developed in cyclic viscoplasticity of semicrystalline polymers with finite strains. Adjustable parameters in the stress-strain relations are found by fitting the experimental data. Ability of the model to describe the characteristic features of the mechanical behavior and to predict the viscoplastic response in cyclic tests is confirmed by comparison of the results of numerical simulation with observations in additional tests.
  • [ X ]
    Öğe
    Two-phase model in viscoelasticity and viscoplasticity of semicrystalline polymers
    (World Scientific, 2012) Drozdov, A.D.; Düşünceli, Necmi
    Observations are reported on isotactic polypropylene in tensile relaxation tests and in loading-unloading tests followed by relaxation after retraction at temperatures ranging from room temperatures up to 100°C. A two-phase constitutive model is developed for the mechanical response of semicrystalline polymers where crystalline and amorphous phases are treated as viscoelastoplastic continua with different laws of plastic flow. Adjustable parameters in the stress-strain relations are found by fitting the observations. Ability of the model to describe characteristic features of the viscoelastic and viscoplastic behavior of polypropylene at various temperatures is confirmed by numerical simulation and comparison of its results with experimental data in additional tests.