Project Title:

A Mathematical Model To Investigate Undercutting and To Optimize Weld Quality

04.10-6576
NAS8-38447
A Mathematical Model To Investigate
	Undercutting and To Optimize Weld Quality
CFD Research Corporation
	3325-D Triana Boulevard
	Huntsville, AL 35805
		H. Q. Yang
(205-536-6576)

Abstract:

	This project is aimed at providing plausible explanations for the undercutting feature
of welds. A mathematical model will be developed to simulate weld pool motion. Particular
emphasis will be placed on the variation of surface tension with temperature and
local concentrations of oxygen and other impurities that may diffuse to the weld
pool surface through shield gas. The spatial variation of concentration, which is
expected to be quite significant, will be properly accounted for. Such variation
has the potential of causing secondary eddies in the weld pool and, hence, the undercutting
feature on the surface. In Phase I, the model will be developed by adapting an existing
CFD code, and a parametric study will be performed to establish the proof-of-the-concept.
In Phase II, the adapted code will be improved, validated, and documented for use
in NASA and the welding industry.

Potential Commercial Application:

Potential Commercial Applications: The mathematical model and computer code could
become an industry standard for optimization of weld conditions and parameters. Such
a capability is crucial for the success of automation of welding processes.