Wyniki wyszukiwania - BazTech

1

Numerical analysis of rod uniaxial tension considering thermo-mechanical coupling effect

Nguyen H. P., Niezgoda T., Derewońko A., Jachimowicz J.

Metallurgy and Foundry Engineering

|

2015

|

Vol. 41, no. 4

189--199

EN

This paper presents numerical analyses of uniaxial tension tests on rods made of a material with elastic-plastic characteristics with mapping the temperature fields generated in the fields of plastic strains. The use of thermo-mechanical coupling algorithms implemented in CAE programs that enable us to enter the parameters of materials dependent on temperature and used to visualize the damage of the samples is presented. The numerical models were validated with experimental research.

PL

W pracy przedstawiono analizy numeryczne testów jednoosiowego rozciągania prętów wykonanych z materiału o charakterystyce sprężysto-plastycznej z odwzorowaniem pól temperatury generowanych w obszarach odkształceń trwałych. Zaprezentowano wykorzystanie algorytmów sprzężenia termomechanicznego zaimplementowanych w programach CAE, umożliwiających wprowadzenie parametrów materiałów zależnych od temperatury oraz stosowanych do wizualizacji zniszczenia próbek. Wyniki symulacji zwalidowano badaniami eksperymentalnymi.

2

Sprzężęnie termomechniczne w analizach numerycznych 3D procesu toczenia części klasy wałek

Nguyen H. P., Derewońko A., Niezgoda T.

Mechanik

|

2015

|

R. 88, nr 8-9CD2

347--355

PL

Przedstawiono analizę numeryczną 3D procesu toczenia części klasy wałek z wykorzystaniem oprogramowania inżynierskiego MSC. Marc oraz z uwzględnieniem sprzężenia między polami odkształcenia i temperatury. W modelu zastosowano zaktualizowane sformułowanie Lagrange’a wraz ze strategią globalnego remeshingu w celu zapobiegnięcia zniekształceniom elementów. Zestawienie uzyskanych wyników analiz numerycznych i wstępnych badań eksperymentalnych z użyciem kamery termowizyjnej potwierdziła przyjęte założenia i opracowany model numeryczny.

EN

The paper presents a 3D numerical analysis of the turning process with the use of MSC.Marc engineering software. The coupling between deformation and temperature fields was considered and the updated Lagrange formulation was used in the analysis. In order to prevent element distortion, the strategy of global remeshing was used. The results comparison of the numerical analysis and the preliminary experimental studies with the use of a thermal imaging camera confirmed the adopted assumption and the developed numerical model.

3

Thermal-mechanical coupled simulation

Nguyen H. P., Derewońko A., Niezgoda T.

Journal of KONES

|

2015

|

Vol. 22, No. 3

161--168

EN

Optimal design of engineering structures and technological processes requires taking into account various factors affecting the state of strain and stresses in the structure. Coupled thermo-mechanical analysis enables, among others, determination of undesirable changes in a body shape resulting from the implementation method of the initially-boundary conditions, for example, time-varying load and physical properties of the material depending on the temperature. They are also used to determine residual stresses remaining after manufacturing to prevent revalued stiffness and rigidity of the designed construction. In this study, coupled thermo-mechanical analysis illustrated by metal machining operation is presented. The commercial code MSC.Marc has been used to develop a coupled thermo-mechanical finite element model of plane-stress orthogonal metal cutting operations. Metal cutting is one of the most important and common manufacturing processes in the car industry. A thermal mechanical transient analysis is performed to convert mechanical work into heat by plastic deformation of the workpiece material and friction during metal machining operation. The finite element mesh distortion, due to large deformations, requires a remesh technique. The influence of parameters of the 2D and 3D finite element mesh adaptation on plastic deformation and temperature generated in the cutting processing is considered.

4

Numerical, experimental and analytical study on MRE used for vibrating pile hammer efficiency improvement

Kwietniewski M., Miedzińska D., Nguyen H. P., Gieleta R., Osiński J.

Journal of Achievements in Materials and Manufacturing Engineering

|

2015

|

Vol. 73, nr 2

151--156

EN

Purpose: of this paper is a research on Vibratory Pile Hammer (VPH) efficiency improvement with the use of Magnetorheological Elastomer (MRE) controlled with external magnetic field. Design/methodology/approach: The analytical equations are made to describe physical dependence of MRE on VPH work. To describe elastomer properties reduced polynomial model proposed by Oon H. Yeoh was used. The shear tests for Magnetorheological Elastomer of two with different volume of carbonyl-iron particles and its influence on elastomer pillow implemented in VPH were carried out. Tests were carried out in external magnetic field and without it. Numerical analyses were conducted with the use of MSC Software applying Finite Elements Method (FEM). The FE model was built on the experimental boundary conditions. Findings: MRE significantly changes elastic properties under applied magnetic field, what can be used to stiffness and damping properties of the construction control. Research limitations/implications: In further analyses, the test results will be used for the evaluation and selection of MRE regulation system. Practical implications: The presented results were used in modification of Vibratory Pile Hammer to improve its efficiency and a maintain device in resonance. Originality/value: The new application of the phenomenon of MRE stiffness change caused by the variable external magnetic field will allow to keep the mechanical system in resonance.