Generalizations of the Finite Element Method

This paper is concerned with the generalization of the finite element method via the use of non-polynomial enrichment functions. Several methods employ this general approach, e.g. the extended finite element method and the generalized finite element method. We review these approaches and interpret them in the more general framework of the partition of unity method. Here we focus on fundamental construction principles, approximation properties and stability of the respective numerical method. To this end, we consider meshbased and meshfree generalizations of the finite element method and the use of smooth, discontinuous, singular and numerical enrichment functions.     

Nonlinear dynamics of parts in engineering systems

By definition, chaotic vibrations arise from nonlinear deterministic physical systems or non-random differential or difference equations. In numerous engineering systems there exist nonlinearities which might affect the dynamic behaviour of the system. The objectives in this work are to summarise previous work on nonlinear dynamics of engineering parts and products and to investigate if research on how nonlinear parts can effect the total behaviour of the products have been performed. It is found that common nonlinear parts are machine elements such as gears, bearings, brakes and suspension systems. The most studied part in a product is of impact hammer type. The products are ordinary products, from sewing machines, drilling machines and printers to railway vehicles. In order to be able to design reliable products the methodology should be further developed to enable use by engineers. One can conclude that the effect of nonlinear parts on the total system behaviour is still a fairly uninvestigated area.     

Zur Bestimmung des Albumingehaltes in Serum, Urin u. a.

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Ges?ttigte L?sungen zur Herstellung von Standardl?sungen

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