An Analysis of Gas Metal Arc Welding Using the Lyapunov Exponent

The characteristics of chaos are unique to the technique of gas metal arc welding (GMAW), which can be safely classified as being a nonlinear process. In this article, salient aspects relevant to the development and use of computational technique to accurately calculate the maximum Lyapunov exponent of the welding processes for different parameters is presented and discussed. The maximum Lyapunov exponent is then used to evaluate stability of the welding process while concurrently aiding in the selection of the welding parameters. Careful analysis of the results reveals overall chaos to exist in the gas metal arc welding process for the different droplet transfer modes. Overall stability of the welding process is related to the chaos that is generated and exists. The maximum Lyapunov exponent can be safely used as a valid criterion for evaluating the stability of the welding process. This aids in the selection of an optimized welding parameter for the welding process to form a weld bead that has both quality and integrity.