Modeling and optimization of resonance characteristics of complex machinery system under dynamic load

The paper deals with the optimization of the dynamic characteristics of a complex machinery system. The algorithms for optimization of the dynamic features have been elaborated and applied for a selection of design variables with the aim of minimizing the vibration amplitudes and optimizing the resonance characteristics of the system. A CAD model of the cutting boom of a continuous miner machine has been selected as an example and was adopted in the LS-PrePost command file. This machine has been selected because it is exposed to complex dynamic forces that cause vibrations and shocks. The paper shows the methodology for the optimization of the modal parameters of the complex mechanical system by using the finite elements method. A new objective function was applied and designed for maximization of the differences between eigenfrequencies and excitation peak force frequencies with respect to the total mass of the system. The genetic algorithm method was used to search for the optimal solution. The influence of parameters on the mass and eigenfrequencies is presented as a result of the sensitivity analysis. During the optimization process, a geometrical parameterized model was applied in order to optimize the system. The results of the modal analysis are part of a complex dynamic simulation of the cutter boom which integrates transmission, drives, and cutting head.