Finite Element Models

Long before the contemporary concept of discretization used in the finite element method (FEM) appeared, so-called physical discretization (or physical lumping in English literature) methods were in active use. There, to solve a continual problem, a system with a finite number of degrees of freedom used to be introduced on the basis of certain physical considerations. For example, recall a method by B.N.Zhemochkin [32] popular as long as thirty years ago, intended for the analysis of beams and slabs lying on an elastic semi-plane and elastic semi-space respectively. Particularly, mechanical bar models used to be constructed, equivalent to continual systems in a certain sense (for example, by accumulated energy). It may seem that the days of those theories are gone, and most researchers have realized that thy physical lumping is much weaker (and more naive) than the contemporary finite element analysis, now that the latter has all attributes of a “serious theory” based on advanced mathematics and theory of continua.