One way to increse the efficiency of numerical methods of modeling the corroding constructions behavior

Authors

  • O. R. Denysiuk State Higher Education Establishment “Ukrainian State University of Chemical Technology”, Gagarina avenue, 8, 49005, Dnipro, Ukraine
  • D. G. Zelentsov State Higher Education Establishment “Ukrainian State University of Chemical Technology”, Gagarina avenue, 8, 49005, Dnipro, Ukraine

Keywords:

aggressive environment, process of corrosive deformation, system of differential equations, decompo sition algorithm.

Abstract

Abstract. Objective. The paper proposes an algorithm of solving differential equation systems modeling the process of change of strain-stress state of statically indeterminate hinged-rod structures over time due to influence of aggressive environments (the process of corrosive deformation). The proposed algorithms allows to minimize numerical cost and at the same time to acquire the solution with necessary accuracy.  Methodology.  The algorithm is based on decomposition of the system which means transforming initial equations by entering into them functions that describe influence of other equations, and then solving one of those equations.  The first stages assumes numerical solution of system of differential equations with minimal number of nodes to determine the num ber of element which determines the durability of structure and to build the approximation function describing change of internal forces over  time.  On  the  second  stage  the  differential  equation  describing  corrosion  process  in  element  with  the  least  durability  is transformed  by  entering  the  acquired  approximation  function  into  its  right  side  a nd  solved  numerically  with  necessary  accuracy. Results. The results of numerical experiments prove efficiency and accuracy of the proposed algorithm. It is shown that the proposed algorithm allows to significantly lower computational cost determining durability of constructions in comparison to the algorithms used before acquiring the solution with the same accuracy. The authors came to conclusion that efficiency of the algorithms d oes not depend on forms and sizes of rod elements.  Scientific novelty. For the first time the possibility of building functions approximating the  change  in  the  internal  forces  of  rod  elements  over  time,  and  solving  a  single  equation  instead  of  the  system  of  different ial equations  is  proposed  and  substantiated.  Practical  significance.  The  most  promising  use  of  this  method  is  in  the  solution  of problems of optimum design of structures with durability constraints. In this case the problem of durability determination is  solved on  each  iteration  of  optimal  design  search,  and  that  leads  to  high  computational  cost.  Application  of  decomposition  method  will  allow to solve the problem with minimal computational cost and high accuracy.

Author Biographies

O. R. Denysiuk, State Higher Education Establishment “Ukrainian State University of Chemical Technology”, Gagarina avenue, 8, 49005, Dnipro

PhD student

D. G. Zelentsov, State Higher Education Establishment “Ukrainian State University of Chemical Technology”, Gagarina avenue, 8, 49005, Dnipro

Dr. Sc. (Tech.), Prof.

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Published

2016-09-27

Issue

Section

Computer systems and information technologies in education, science and management