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An economical storage organization for large and small finite element systems with reference to the application of iterative approximation methods to nonlinear material behaviour
Author(s) -
Fengels W.,
Troost A.
Publication year - 1980
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.1620150507
Subject(s) - subroutine , fortran , computer science , nonlinear system , finite element method , magnetic tape , transfer (computing) , iterative method , element (criminal law) , parallel computing , algorithm , computer hardware , structural engineering , engineering , physics , digital recording , quantum mechanics , law , political science , operating system
The method of data transfer from the peripheral storage unit to the central processor unit, when dealing with large solution systems, is of greater importance, as each access of peripheral stored data interrupts the active flow of arithmetic operation in the central processor core. When solving a large number of symmetrical positive‐definite equations this generally leads to difficulties in channel interaction and priority, possibly even to the breakdown of the computer system or to uneconomical computing times. The problem increases when considering the iterative approximation of nonlinear problems; further still, when using the frontal solution method. It will be shown that this difficulty can be avoided by inserting two different types of buffers—a micro‐buffer and a macro‐buffer—into the data transfer between the central memory and an arbitrary peripheral storage unit. This method should primarily be used in those finite element (FE) programs which are based on the ‘slow’ BACKSPACE‐READ‐BACKSPACE commands, but even in the case of peripheral storage units such as magnetic discs (random access) or magnetic tape machines (working in one or two directions) the computing time and channel control can successfully be improved. A second achievement of this procedure is the possibility of applying a FE program economically, not only to large element systems and elements of a ‘higher order’ but also with good results for small element systems, e.g. when investigating nonlinear material behaviour with simple element types and geometrical structure. Another purpose of this text is to recommend the FORTRAN subroutine in the Appendix, whose novel features make it a useful supplement to ‘nonlinear’ FE programs.