U. Chandra, G. Barot, Modern Computational Technologies, Inc., Cincinnati, OH
This presentation will discuss the ongoing effort in the development of finite element models for computer simulation of the electron beam freeform fabrication (EBF3) process under a NASA funded Small Business Innovation Research (SBIR) program. Although the present effort deals primary with on-ground fabrication it further serves as a starting point for eventual development of the methodology for in space fabrication. The presentation will include highlights from Phase I as well as Phase II of the effort. Phase I of the program dealt primarily with the thermal and mechanical models of the process. Multi-layered deposits of stainless steel 304 were investigated using a commercial code, ABAQUS. Several issues of practical significance were addressed; e.g., thermal management during fabrication, inter-layer fusion, reheating of the previously deposited material, residual stresses/distortions and an often used method of estimating solidification morphology. A parametric study was also performed. Current efforts in Phase II of the program include further refinements in the thermo-mechanical model, development of microstructure models, study of the role of convection in the melt pool, and experimental validation using geometries of moderately complex shapes.
Summary: This presentation will discuss the ongoing effort in the development of finite element models for computer simulation of the electron beam freeform fabrication (EBF3) process under a NASA funded Small Business Innovation Research (SBIR) program. Although the present effort deals primary with on-ground fabrication it further serves as a starting point for eventual development of the methodology for in space fabrication. The presentation will include highlights from Phase I as well as Phase II of the effort.
Phase I of the program dealt primarily with the thermal and mechanical models of the process. Multi-layered deposits of stainless steel 304 were investigated using a commercial code, ABAQUS. Several issues of practical significance were addressed; e.g., thermal management during fabrication, inter-layer fusion, reheating of the previously deposited material, residual stresses/distortions and an often used method of estimating solidification morphology. A parametric study was also performed. Current efforts in Phase II of the program include further refinements in the thermo-mechanical model, development of microstructure models, study of the role of convection in the melt pool, and experimental validation using geometries of moderately complex shapes.
