A. V. Demidov

A version of modeling of nonlinear-hereditary viscoelasticity of polymer materials

We propose a version of the mathematical model of nonlinear-hereditary viscoelasticity of polymer materials, which is used to predict strain processes of various complexity, from simple relaxation and simple creep processes to complicated strain recovery processes and reverse relaxation processes with alternating loading and unloading.

Modeling of Deformation-Relaxation Processes of Aramid Textile Materials – the Foundation for Analyzing Their Operational Properties

Methods for mathematical modeling of deformation-relaxation processes of aramid textile materials are described. It is shown that the increase in the competitiveness of these materials is closely tied to qualitative analysis methods of their operational-consumer and functional properties.

Variants of Mathematical Simulation and Systems Analysis of Mechanical Relaxation and Creep of Polymer Materials

Questions related to mathematical simulation and systems analysis of mechanical relaxation and creep of polymer materials are considered. Based on this discussion a prediction of relaxation and deformation processes of differing degrees of complexity, from simple relaxation with constant deformation and simple creep with constant load to compound processes of reverse relaxation and deformation-reduction processes with multi-stage deformation and loading, is presented.

Mathematical Modeling and Computer Prediction of Deformation Processes in Polymeric Parachute Straps

Aspects of the mathematical modeling and computer prediction of deformation processes in polymeric parachute straps are examined. The computer methods developed on the basis of the mathematical model of viscoelasticity to predict relaxation and creep in the straps make it possible to calculate deformation and relaxation processes and the straps’ relaxational and deformational characteristics with a high degree of accuracy. Methods that were developed to divide total strain into its components also allow evaluation of the straps’ elastic and viscoelastic properties, which play an important role in choosing materials that have the requisite deformation properties.

Spectral Analysis of Relaxation Properties of Polymer Yarns with an Amorphous/Crystalline Structure

Spectral analysis of relaxation properties of polymer yarns is used to give a physical interpretation of systems analysis methods and computational prediction of nonlinear hereditary relaxation of yarns with an amorphous/crystalline structure in the zone of nondestructive mechanical action. Spectral modeling of the relaxation properties of polymer yarns is based on a generalized classical Maxwell model. The selected normalized relaxation function is interpreted as the integrated particle distribution with respect to a logarithmic relaxation time scale. Such a physical interpretation of the relaxation function is useful for comparative analysis of the relaxation properties of polymer yarns.

Spectral Analysis of the Deformation Properties of Polymeric Filaments with an Amorphous-Crystalline Structure

A spectral analysis of the deformation properties of polymeric filaments is performed to obtain a physical interpretation for methods which employ systems analysis and entail computational prediction of the nonlinear hereditary creep of amorphous-crystalline filaments under non-destructive mechanical loads. Spectral modeling of the filaments’ deformation properties is done on the basis of the classic generalized Kelvin-Voigt-Meyer model. The normalized memory function which is chosen is interpreted as an integral function that describes particle distribution on the logarithmic scale of lag time. Such a physical interpretation of the memory function is useful for comparatively analyzing the deformation properties of polymer filaments. This article is a continuation of the research that was begun in [1].