Numerical modeling of large elastoplastic strains in terms of principal stretches. II. Physical relations, calculation algorithm

The constitutive relations and plastic flow rule are derived from the thermodynamics equations. The known procedures of determining the plastic strain rate value are described. A calculation algorithm is presented that is based on the incremental loading, linearization of the virtual power equation and the projection method. A numerical example is presented. © 2010 Allerton Press, Inc

Finite strains: Objective rates, conjugate stress tensors, constitutive equations for composite materials

Theoretical problems of the kinematics of continuum under the conditions of finite strains are considered; the technique for development of constitutive equations for isotropic and composite hyperelastic media is presented. A system of principal directions of the left and right tensors of distortions that determine material (Lagrangian) and spatial (Eulerian) tensors are taken as a basis. Such an approach allows construction of stress tensors conjugate to any strain tensor which is demonstrated by a number of examples. 2152-2057/10/$35.00©2010 by Begell House, Inc

Numerical modeling of large elastoplastic strains in terms of principal stretches. I. kinematics of elastoplastic strains

A technique for numerical finite element analysis of large elastoplastic strains is proposed. A problem is formulated in terms of principal stretches and their logarithms in the current basis of the left distortion tensor. It is shown that the "classical" multiplicative decomposition of the total strain gradient into the product of elastic and plastic strain gradients is equivalent to the presentation of total stretches as a product of elastic and plastic stretches. © Allerton Press, Inc., 2010

Algorithmic means implementing requirements reliability entering information into the onboard control computing system in rocket "SOYUZ-2"

Рассмотрены предъявляемые требования по надежности к режиму ввода программного обеспечения в бортовую цифровую вычислительную систему ракеты-носителя «Союз-2». Произведен анализ существующих программно-алгоритмических средств обеспечения предъявленных требований по надежности. Из-за большого количества используемых элементов и возрастания объемов хранимой информации возникает ряд проблем связанных с реализацией надежного ввода. Основные проблемами в данном режиме это большая вероятность возникновения двух кратных искажений информации и внешнее воздействие на линии связи. В связи с этим представлены доработанные программно-алгоритмические средства обеспечения надежности режима ввода программного обеспечения, с учетом особенностей и возможностей бортовой цифровой вычислительной системы ракеты-носителя «Союз-2», существенно повысившие надежность режима ввода и системы в целом.Discussed requirements to in terms of reliability to the input mode software onboard digital computer system rocket "Soyuz-2". The analysis of existing software and algorithmic means to ensure demand under reliability. Due to the large number of elements used and increasing volumes of stored information, a number of problems associated with the implementation of a reliable input. The main problem in this mode is a large probability of two multiple misstatements and external influence on the link. In this regard, presented the modified software and algorithmic means of securing the input mode information, taking into account the characteristics and capabilities of the onboard digital computer system carrier rocket "Soyuz-2", will significantly increase the reliability of the input mode and the system as a whole