Wyniki wyszukiwania - BazTech

1

Methodology of Comparative Validation of Selected Foundry Simulation Codes

Ignaszak Z., Popielarski P., Hajkowski J., Codina E.

Archives of Foundry Engineering

|

2015

|

Vol. 15, iss. 4

37--44

EN

The validation of each simulation code used in foundry domain requires individual approach due to its specificity. This validation can by elaborated on the basis of experimental results or in particular cases by comparison the simulation results from different codes. The article concerns the influence of grey cast iron density curve and different forms of solid fraction curve Fs=f(T) on the formation of shrinkage discontinuities. Solid fraction curves applying Newtonian Thermal Analysis (NTA) were estimated. The experimental and numerical simulation tests were performed on the castings, which were made with Derivative Thermal Analysis (DerTA) standard cups. The numerical tests were realized using NovaFlow&Solid (NF&S), ProCast and Vulcan codes. In this work, the coupled influence of both curves on the dynamics of the shrinkage-expansion phenomena and on shrinkage defects prognosis in grey cast iron castings has been revealed. The final evaluation of the simulation systems usefulness should be based on validation experiment, preceded by comparing the simulation results of available systems which are proposed in given technology.

2

Macro model of seat belt use by car drivers and passengers

Jamroz K.

Transport Problems

|

2013

|

T. 8, z. 4

103--114

EN

The article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.

PL

W przedstawionym artykule przedstawiono poruszono niektóre zagadnienia dotyczące stosowania pasów bezpieczeństwa przez kierowców i pasażerów w pojazdach. W szczególności przedstawione zostały problemy stosowania pasów bezpieczeństwa w wybranych krajach oraz ich skuteczność. Następnie przedstawiono czynniki wpływające na poziom stosowania pasów i metodykę opracowania modelu. Przedstawiono także makroskopowy model używania pasów bezpieczeństwa opracowany na podstawie danych z kilkudziesięciu krajów z różnych kontynentów.

3

Model of pure metal solidification using the power-type function

Mochnacki B., Szopa R.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

Vol. 22, nr 1

65-68

EN

Purpose: The typical mathematical descriptions of pure metal solidification (micro/macro approach) base on the linear or exponential (Kolmogoroff) models. In the paper the possibilities of such models modification are presented. This new model can be called a power type one. The approach proposed can be usefull on the stage of numerical simulation of solidification on the micro/macro scale. Design/methodology/approach: The local and temporary volumetric fraction of solid state is described by the equation from which both the linear and exponential model can be obtained. Introducing the additional parameter to this equation the new solidification model is found. Findings: The method here presented allows to determine the transient temperature field in a non-homogeneous system casting-mould and to observe the course of metal solidification. The obtained cooling curves allow to observe (contrary to macro models) the recalescence effect. Practical implications: The solidification model in a version presented in this paper can be an effective tool for numerical simulation of solidification process. Originality/value: The concept of introduction of power-type function for the mathematical description of micro/macro solidification model is original and gives the new possibilities numerical methods application in a thermal theory of foundry processes.