Vibration Analysis of Washing Machines in the Drum Plane

Abstract

In this study, a nonlinear mathematical model for drum-type washing machines is developed considering rotating unbalance type excitation. Nonlinear differential equations of motion are converted into a set of nonlinear algebraic equations by using harmonic balance method (HBM). The resulting nonlinear algebraic equations are solved by using Newton’s method with arc-length continuation. Several case studies are performed in order to observe the effects of orientation angles of springs and dampers supporting the drum. In order to reduce the steady-state vibration amplitude of the drum and transmitted force through springs and dampers, suitable spring and damper orientation angles are identified. Moreover, in order to further reduce the vibration amplitude of the drum, dry friction dampers are introduced to the system. It is clearly observed that dry friction dampers are solving the walking problem of washing machines.