Wyniki wyszukiwania - Biblioteka Nauki

1

Identification of mechanical parameters of bone tissue as a base of numerical simulation in medicine

100%

John A. , Kokot G.

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tom Vol. 83, nr 2

49--67

EN

Purpose: The aim of the paper is to show the new possibility of evaluation of bone tissues properties in experiment and next the numerical simulation and verification of selected problems. Design/methodology/approach: The lifestyle that has been favored lately has led to unfavorable changes in the human body. This is manifested mainly by joint anomalies and changes in the structure of bone tissue. The scientists try to aid the healing and rehabilitation systems. It is possible to prepare a numerical model of complex biomechanical structures using advanced FE systems. The process of modeling is one of the most important steps of this research and assignment of material data influences on the precision of obtained results. The classic measurement methods with particular emphasis on their application in the study of bone, taking into account the advanced methods for measuring displacement are applied (DIC, nanoindentation). Also QCT combined with evolutionary methods gives interesting results in identification of material parameters Numerical simulations are verified in experiment. Findings: Obtained results allow to compare the displacement and strain from experiment and numerical simulation. From numerical simulation, after FEM analysis we obtained full set of mechanical parameters useful in planning of surgical intervention (THA, pelvis reconstruction), aided the diagnostic in risky state and design of prosthesis. Research limitation/implications: The precision of identification of material parameters depend on many parameters and influences on the precision of the results from numerical simulation. Research is conducted mainly on preparations and not on living tissue. The target should be in-vivo noninvasive measurement. Originality/Value: Combination of numerical simulation and experimental research is needed to obtain correct results and broaden the spectrum of relevant parameters necessary to support surgical and rehabilitation. Both approaches require modern equipment and advanced testing methods.

2

Numerical analysis of stress and strain in planetary wheel of cycloidal gear using FEM

80%

Chmurawa M. , John A. , Kokot G.

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tom nr 13

45-50

EN

The complex construction of planet wheels in cycloidal planetary gear (Cyclo) practically makes impossible its optimal design. To calculate distribution of strains and stresses in planet wheels with co-operating elements FEM has been implemented. There were series of numerical models of planet wheels generated and for example of real model of gear it has been calculated proper values of forces, strains and stresses. In the paper forces and strains calculated with FEM have been used to check the assumptions, which have been applied only in analytical so far.

PL

Konstrukcja kół obiegowych w przekładni cykloidalnej (Cyclo) praktycznie uniemożliwia ich optymalne zaprojektowanie. Do obliczeń odkształceń i naprężeń w kołach obiegowych zastosowano MES. Utworzono :|: szereg modeli współpracy kół obiegowych z elementami współpracującymi na przykładzie rzeczywistej przekładni. Obliczone MES siły i wykorzystano do zweryfikowania założeń, stosowanych dotychczas w metodzie analitycznej.

3

Advanced numerical simulations of selected metallurgical units

80%

Kokot G. , Burczyński T. , John A.

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tom Vol. 55, nr 2

523--528

EN

Purpose: of this paper is to present numerical simulations of large structures in metallurgical industry. Some examples of finite element analysis are presented. The calculations were performed for the determining the stress effort of the metallurgical units mainly blast furnace, throath’s gas pipelines, hot blast stoves, etc. during the working conditions and for the repairing purpose. Design/methodology/approach: The way of conducting simulations and analysis were the finite element method connected with the optimization process. Findings: Performing the numerical analysis the changes in the structures design were applied what extremely influenced on the state effort and the durability of considered structures. Research limitations/implications: Development of the presented approach solving the coupled field and CFD problems, the application of the parallel computing and domain decomposition methods in the large structure simulations. Practical implications: Presented results shows the possibility of application the advanced computational methods in the computer aided engineering processes of designing and analysing the large structure as the metallurgical units are. It can dramatically influence on the recognizing of the effort stets and helps in the monitoring, overhauls and redesigning process. Those methods gives the global very precise information which cannot be obtain in other ways (analytical solutions, experimental methods). Originality/value: The paper present the original research results comes from the complex numerical simulations of the main metallurgical units in the blast furnace train. The original value of the paper is the introduction of the advanced finite element simulation in the field of iron steel industry structures design and developing.