Design Optimization of a Laser Cutting Machine by Elastodynamic Modeling

This study deals with the elastodynamic modeling of a laser cutting machine and illustrates the guidelines followed for the design optimization of the machine’s basic structure from the dynamic behavior point of view. A finite element model was set up along with the conceptual design of the new machine, with the aim of performing dynamic simulations. The main purpose is to predict the vibrations arising in the structure that could significantly deteriorate the product quality in order to evaluate different design solutions. The vibrations can be excited by variable forces acting on the moving masses and by the oscillations affecting the machine basement due to external causes. The original modeling of the excitations is presented herein. Modal analysis and forced simulations were performed on the finite element model of the first conceptual design of the machine structure. The analysis of the results indicated some critical parts of the system to be stiffened in order to mitigate the vibrations, that is to improve the cutting quality. Structural modifications to the first conceptual design were therefore suggested and a new model of the machine was developed and simulated. The results of the simulations before and after the design modifications are reported and discussed.