A semi-physical and semi-intelligent heat source model based on keyhole heat transfer and energy attenuation

At present, the laser welding heat source model is mainly loaded in the form of energy density distribution in geometric regions, and its accuracy is closely related to the geometric region size of energy distribution. However, it lacks a mapping relationship with laser process parameters and physical mechanisms, making it difficult to use for constructing digital twin technology for laser process equipment. In response to this issue, a semi-physical and semi-intelligent heat source model based on laser welding keyhole heat transfer and energy attenuation was proposed. Firstly, based on the physical mechanism of heat transfer in laser welding keyhole formation, the nonlinear geometric region of laser energy distribution was determined through algorithms; Then, based on the absorption rate attenuation phenomenon of the laser along the depth direction of the material, a knowledge-based nonlinear attenuation curve parameter was defined to express the attenuation law of laser energy. By combining the above two methods, a semi-physical and semi-intelligent heat source model was established. The results verify the rationality and accuracy of the heat source model through experiments and simulations of 316L stainless steel laser welding. On this basis, the mapping relationship between heat source model parameters and laser power, defocus, and welding speed is explored, laying a foundation for the digital twin implementation of laser welding technology.