VIBRATION RESPONSE ANALYSIS AND STRUCTURAL OPTIMIZATION OF A MULTISTORY RACK UNDER MECHANICAL EXCITATION

Vibration response of a multistory rack under mechanical excitation, which is caused by machine destruction, provides the basis for the condition monitoring of the system. Analysis of the response is the precondition for the anti-impact performance design. A multistory rack with 15 machines fixed on its beams is taken as an engineering example to carry out this study. The machine-rack system is discretized into a dynamic system with more than 20 degrees of freedom. Kinematic equations of the machine-rack system is obtained with Lagrange method and solved by Runge-Kutta method. Dynamic response of the system under typical mechanical is attained. Both the vibration mode of each beam and dynamic amplification factor of the system are calculated. In order to improve the performance of the system under typical mechanical excitation, the structural optimization is carried out. Particle Swarm Optimization (PSO) algorithm is used in this research so as to achieve the best values of design parameters of the system. It is proved that the anti-impact performance of the system can be significantly promoted based on the optimization.