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FEM simulation of pulsed laser seam welding
Lapšanská, Hana ; Havelková, Martina ; Chmelíčková, Hana
Welding simulations became very popular in last years because they can provide us with much interesting information about the internal material processes or heat source – material interactions. Usually continual seam welding was simulated. Since the pulsed laser welding systems were developed and disseminated, the need of pulsed welding simulations came out. Finite element SYSWELD welding simulation tool was adapted to model and simulate pulsed laser seam welding, also called spot overlapping welding. This paper describes basic principles of such simulation and shows some of its possible outputs.
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Laser welding of stainless steel tubes
Chmelíčková, Hana ; Lapšanská, Hana ; Hiklová, Helena ; Havelková, Martina
Laser axial welding is a modern method of production of tubes with seam which are mainly used in automotive and food-processing industry. Welding experiments with AISI 304L stainless steel sheet were conducted using continual high power CO2 laser with maximal power 5 kW. The aim of these experiments was to evaluate the effect of processing parameters on weld dimensions and surface properties. Subjected parameters were laser power, shielding gas flow and its composition. Modern contact profilometry was applied to display weld surfaces. Metallographic specimens of weld cross sections were prepared to measure the weldarea. Temperature field distribution was modeled using finite element software SYSWELD.
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Optical methods in non-contact velocity measurement
Šmíd, Petr
The paper presents an overview of some interesting methods using optical and sound waves for non-contact velocity measurements. The paper focuses mainly on optical techniques using different optical principles as interferometry, image analysis and processing, and speckle effect.
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Numerical modelling of the glass shaping forms cooling
Havelková, Martina ; Schovánek, Petr
The purpose of heat treatment of semi finished glass pieces in shaping forms is not only to fit their shape but also to reduce internal stresses. Thermal differences are unwanted and have to be eliminated in the cooling procedure of the glass pieces. Simulations of different types and sizes of shaping forms and complex model cooling were accomplished. The aim of these simulations was to optimise geometrical parameters, clamping conditions and material of the form, so that thermal differences at glass or glass – form interface are minimized during the cooling.
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Preparation of ZnO Layers by Surfatron with Possible Photo-Catalytic Usage
Dytrych, Pavel ; Slater, M. ; Klusoň, Petr ; Churpita, Olexandr ; Hubička, Zdeněk ; Čada, Martin ; Morozová, Magdalena ; Zita, B. ; Krýsa, J. ; Straňák, Vítězslav
Pecvd method in this contribution we deal with the preparation of thin layers of ZnO, which exhibit interesting photo-sensitive properties. ZnO functional layers were prepared by surfatron by a PECVD method.
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