Electric arc additive forming prediction modeling method based on molten drop transition

Abstract

The invention provides an electric arc additive forming prediction modeling method based on molten drop transition, and relates to an electric arc additive forming process numerical calculation modeling method. According to the modeling method, the molten pool flow field calculation and a molten drop transition process are coupled, a computational domain is updated by adopting a dynamic grid technology and considering the movement of a welding gun, and transportation equations are uniformly solved in a molten pool computational domain and a molten drop transition computational domain, so thatthe simulation prediction of electric arc additive manufacturing forming morphology, temperature field and flow field is achieved, and the problems that the size of an existing arc additive cladding layer cannot be predicted and the physical field evolution is not clear are solved. The method is implemented through the following steps of 1, establishing a material and geometric model, and definingthe computational domain and boundary conditions; 2, establishing a molten drop mechanical model, and determining a molten drop transition computational domain transportation equation source item; 3,establishing a molten pool thermodynamic model, and determining a molten pool computational domain transportation equation source item; and 4, loading a thermodynamic source item, and uniformly solving molten drop and molten pool computational domain transportation equations.

Description

technical field [0001] The invention relates to a numerical calculation modeling method for arc additive manufacturing, especially for the simulation prediction of the forming morphology, temperature field and flow field of the cladding layer in the arc additive manufacturing. Background technique [0002] Additive manufacturing technology is a technology that uses metal or non-metal materials to directly form three-dimensional components layer by layer based on CAD models. It is a leading technology for the transformation from mass manufacturing mode to personalized customization mode. Metal additive manufacturing technology uses arc, laser or electron beam as the heat source, and realizes the printing of components by melting welding wire or powder. The whole process does not require molds, high production efficiency, high material utilization rate, and low cost. [0003] Forming accuracy and formability are two core issues in metal additive manufacturing. In general, the...

AI Technical Summary

Problems solved by technology

However, most of the calculations of temperature field, stress field, and flow field in arc additive manufacturing are based on the simulation analysis of the previously drawn cladding layer morphology. When the process parameters are changed, the cladding layer morphology changes, and it is necessary to rebuild model, which undoubtedly greatly increases the workload of simulation

The above defect can be improved by adding the mass source term in the mass conservation equation to directly predict the cladding layer morphology, but this method ignores the complex force of the droplet transfer process and the impact on the molten pool after entering the molten pool. shocks, which somewhat limits the accuracy of simulation predictions

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