Connection laser weldin temperature field numerical simulation based on ANSYS
As the most important welding process in the welding, the laser welding has become a hot field of the study due to its large welding depth and high welding efficiency, and therefore many researchers have conducted a lot of investigation about laser welding connection technology. The weldpool geometry and temperature and the distribution of the heat source are crucial for the welding quality. Although there are many experimental and theoretical researches of the laser welding connection, most of them focus on the weldpool shape, thermal stress, and also the stability of the welding pool and Q characteristics. To advance the research level, the numerical simulation on the laser welding temperature field is a effective way to analyze the welding effect by computer.
ANSYS is a software that can offer an interference free three-dimensional (3D) heat exchange function of the heat source, which has been broadly used in the study of laser welding temperature field. This software can describe the how of the heat entity by the conduction heat transfer equation, and then the heat source which is 3D can be established. By setting the quality collecting point according to the requirement of the laser welding connection, the welding temperature field can be simulated. The detailed process of the temperature field simulation can be divided into the model setting, material property definition and boundary conditions definition, and the model solving.
In the model setting of the laser welding connection based on the ANSYS, it is important to resolve the mathematical model in a structurally correct way. During the laser welding procedure, the object can be divided into different parts, such as the welding object, gases and ablated particles, the heat sink and so on. According to the analysis object, the appropriate model can be selected, such as the shell model, 3D solid model or the assembly solid model. In general, the 3D solid model is commonly used to simulate the welding process.
The material property definition is the core part for the establishment of the mathematical model. In the laser welding process, many different materials are involved, and the material parameters which used in the simulation should respected their properties and feature. The ANSYS software provides a big range of materials and the material property can be edited to match the actual welding material involved in the numerical simulation. The thermal conductivity should be set properly based on the change of the temperature field. The other material parameters should also be pay attention to, such as specific heat capacity and thermal parameter.
The boundary conditions are vital to the thermal field calculation. In the laser welding simulation, the boundary conditions include the constraints at the edge of the laser, the temperature of the surface, the boundary of the model and the boundary of the boundary fields. As for the boundary of the boundary fields, if the welding process involves the welding objects and the heat sink, the boundary conditions should be distinguished. The boundary of the laser model surface should be the metallized surfaces and the boundary value should be set as the maximum temperature of the welding surface.
The model solving is the last step for the laser welding numerical simulation based on the ANSYS. After setting up the mathematical model and defining the materials properties and boundary conditions, the exact parameters should be determined for the numerical calculation. Then this software can offer an automatic solution to solve the model by defining the integration point number and the convergence criteria and so on.
In conclusion, the numerical simulation technology of the laser welding based on the ANSYS can provide a powerful means to understand the welding temperature field in detail, which is very meaningful for the quality control of the welding process. To gain accurate calculation results, it is important to establish the structural reasonable mathematical model and define the material properties, boundary values and the model solving parameters successfully.
