A numerical formalism towards finding a good component orientation in laser powder bed fusion

Abstract

Several manufacturing constraints and objectives are considered when choosing a build orientation for laser powder bed fusion (LPBF) parts. Some of them are inversely proportional to one another making it necessary to formalize an optimization scheme with weighting factors enabling engineers to decide which of them is most relevant for the application under consideration. Several of the considered cost functions are quick to calculate (e.g. down skin area). The reduction of residual stresses and distortion are on the other hand computationally intensive and are not easily considered in an optimization scheme. Solution sampling in 3 angular directions is therefore utilized to create a response surface describing the part distortion in arbitrary orientations. The response surface accuracy is studied before applying it together with 7 other cost functions within a multi-objective Monte-Carlo optimization scheme.

Keywords

• Additive manufacturing
• Powder bed fusion
• Multi-objective optimization
• Distortion