Finite element modeling method of macroscopic thermal stress field based on self-healing effect of laser stereoforming

Abstract

A finite element modeling method of macroscopic thermal stress field based on the self-healing effect of laser stereoforming in the present invention comprises the following steps: step 1, establishing a thermomechanical coupling model for unilateral clamping of a laser stereoforming substrate; step 2, establishing a laser stereoforming Thermal-mechanical coupling model of the i-th cladding layer of the formed component; Step 3, calculate the temperature field of the i-th cladding layer of the laser three-dimensional forming component; Step 4, calculate the stress field and deformation of the i-th cladding layer of the laser three-dimensional forming component ; Step 5, judging whether the bulge on the deposition surface of the i-th cladding layer of the component can be eliminated; Step 6, judging whether the i-th cladding layer is the last layer; In the case that the process is eliminated, if the i-th cladding layer is the last layer, the simulation processing ends, otherwise, enter step 2, and repeat this cycle until the macroscopic thermal stress field simulation calculation of the entire laser stereoforming is completed.

Description

technical field [0001] The invention relates to thermal stress field finite element modeling in the additive manufacturing process of synchronous material feeding, in particular to a macroscopic thermal stress field finite element modeling method based on the self-healing effect of laser three-dimensional forming. Background technique [0002] Laser additive manufacturing technology is an advanced material forming manufacturing process method. This method adopts the principle of point-by-point-line-by-layer-layer-by-layer accumulation to manufacture three-dimensional parts. It can directly manufacture complex parts on the substrate, with fast and mold-free manufacturing. It can produce extremely complex structures, such as lattice structures, thin-walled complex structures, and conformal inner runners, and has been successfully applied in aerospace, medical, mold and other fields. However, the characteristics of additive manufacturing are non-uniform (inhomogeneous temperatu...

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Problems solved by technology

The simulation results show that the top layer of the single-arm wall has sharp corners and the middle of the top layer is concave, but the actual top layer of the single-arm wall has an arc transition, and the top layer surface is flat without concave-convex fluctuations. Therefore, the residual deformation predicted by the thermal-mechanical coupling model is consistent with that of Actually there is a big error

In the thermal-mechanical coupling simulation of additive manufacturing, the average thickness of the deposition layer is usually used for the thickness of the deposition layer. The entire thermal-mechanical coupling model is generated at one time before calculation, so the relationship between the previous layer of cladding layer and the subsequent layer of cladding layer is not considered at all. The influence of deposition thickness, temperature field, stress field and deformation is a main factor that the traditional thermal-mechanical coupling model cannot accurately predict the laser stereoforming process, so the thermal-mechanical coupling model of laser stereoforming needs to be further optimized

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