Wyniki wyszukiwania - BazTech

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Chosen Solutions Of Computer Lumbar Spine Segment Modeling

Araszkiewicz M., Topoliński T.

Journal of Polish CIMAC

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2009

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Vol. 4, no 3

9-15

EN

For many reasons Finite Element Method is very useful especially in biomechanical researches .One of them is difficulty of gaining real specimens for in vitro tests. The second one is that FEM provides relatively easy way to check how changing some parameters of spine geometry or materials, influences on spine segment behavior. Consider it, many research centers in whole world in last years started to prepare FEM models of spine. Some of them are quite simple, some are very advanced. This paper is a review of three chosen FEM lumbar spine models, made in different scientific centers in last years. Authors present their opinions about possibilities of using material coefficients of particular structures of spine in own model. It could be useful for anybody who wants to build proprietary spine model. Authors met many problems trying to obtain material coefficients from literature which may be adopted to own spine model. Models reviewed in this paper could be important assistance for creating own spine models.

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Frequencies and modes of rotating flexible shrouded bladed discs-shaft assemblies

Sokołowski J., Rządkowski R., Kwapisz L.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 2

215-231

EN

It is now increasingly necessary to predict accurately, at the design stage and without excessive computing costs, the dynamic behaviour of rotating parts of turbomachines, so that resonant conditions at operating speeds are avoided. In this study, global rotating mode shapes of flexible shrouded bladed disc-shaft assemblies are calculated. The rotating modes have been calculated by using a finite element cyclic symmetry approach. Rotational effects, such as centrifugal stiffening have been accounted for, and all the possible couplings between the flexible parts have been allowed. Gyroscopic effects have been neglected. The numerical results have been compared with the experimental. The calculations show the influence of shaft flexibility on the natural frequencies of shrouded bladed discs up to four nodal diameters for the two first frequencies series.

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Problem brzegowy dla tarczy cienkiej o zmiennej sztywności

Wyciślok P.

Szybkobieżne Pojazdy Gąsienicowe

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1999

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nr 12

83--96

PL

W pracy dokonano wyprowadzenia równań różniczkowych problemu tarcz, przy założeniu ich zmiennej grubości. Dodatkowo założono możliwość zmiany własności materiałowych. W obliczeniach uwzględniono wpływ stacjonarnego pola temperatur. Część pierwsza artykułu zajmuje się ustaleniem założeń, idealizacją problemu oraz podaje i wyprowadza podstawowe wzory wyjściowe dla sformułowania problemu.

EN

The paper shows the method to derive differential equations for discs problem, with assumption of their variable thickness. Additionally possibility to change material qualities was assumed. Stationary temperature field was taken into account. Assumptions were established in first part of the paper. Moreover the problem was idealised and basic equations stated or derived to formulate the problem.