Research And Development Of Visualization System For Numerical Simulation Of Laser Welding Based On Visualization Toolkit

Laser welding is a processing method which uses high energy density beam, and it has the advantages of high efficiency, little welding spatter, small heat effected zone and even seam. From the early 90's of the 20th century, laser welding has become the specific welding method of connecting and forming the work pieces which are precision, sensitive and with complex geometry. And also, laser welding is a fast and uneven thermal cycling process. The heat transfer, mass transfer and the flow of molten pool in the welding process effect and decide the structure and performance of the welding joint. Therefore, researching the effect of process parameters on the welding quality is the key to the welding research. However, the welding process experiment can not analyze the physical transmission mechanism during the welding quantificationally. Thus, the implementation of numerical simulation technology in the laser welding is thereupon springing up.With the rapid development of computer software and hardware technology, computer numerical simulation has been implemented in the filed of laser welding widely which pushed the development of laser welding technology forward. Through building the complex physics model of welding process, by means of efficient algorithms and using the computer programs to do the experiment, the researchers can obtain some important data about the temperature and the pressure distribution and the flow of the molten pool which can not be obtained through the process experiment.Numerical simulation of laser welding will produce large amount of analysis data. For the researchers and the technologists, they care about the connection and the pattern between them more than the data themselves. Meanwhile, we need the visualization system for the numerical simulation to visualize the result. The visualization system can transfer these abstract and bald data into the graphics or the images which are more acceptable, and can help the researchers and the technologists understand the heat transfer, mass transfer and the flow process of the micro cell during the welding process more intuitively. At present, there is no specific research on visualization system for numerical simulation of laser welding. On this background, this article chooses the Visualization Toolkit to be the algorithm basic and develops a visualization system for numerical simulation of the molten flow of laser welding based on the object-oriented technology and numerical simulation of laser welding.Firstly, this article studies the class architecture, the encapsulation mechanism of graphic algorithms and the image render pipeline of the Visualization Toolkit, and it resolves the problem with the algorithms of the visualization system.Secondly, this article extends the data interface of VTK and develops the specific data interface for the result data of numerical simulation of laser welding.At last, this article gives out the design and implementation method of visualization system for numerical simulation of laser welding in detail. The system realizes the real time reading the temperature field, fluid field and other magnanimity data, displaying dynamically and quantitative analysis of micro cell. And it supports the basic manipulation of 3D graphics and multiple render methods including advanced volume rendering and iso-surface rendering.It is demonstrated that the visualization system for numerical simulation of laser welding based on the Visualization Toolkit can read the visualization data, and display the temperature field, fluid field and pressure filed of the micro cell of molten pool dynamically in various ways. It supports multiple advanced render methods including volume rendering and iso-surface rendering, and can help the researchers and the technologists understand the physical transfer process of laser welding more intuitionistic.