Model Order Reduction for Design of Torsional Disk Couplings

Torsional couplings are used to transmit power between various rotating components of power systems while allowing for relatively small misalignments that may otherwise lead to equipment failure. When selecting a proper coupling type and size, one has to consider three important conditions: (1) maximum load applied to the coupling, (2) maximum operation speed and (3) amount of misalignment allowable for normal operation. There are many types of flexible couplings that use various materials for the flexible element of the coupling on the market today. Design of the coupling and the materials used for the flexible elements determine the coupling's operating characteristics. In this project, we study metal disk couplings. Benefits of this type of coupling include: ease of replacement or repair, clear visual feedback of element failure, and the absence of a need for lubrication. The torsional stiffness of a coupling is a major factor relative to the amount of misalignment allowable. Currently, flexible couplings are tested by manufacturers to experimentally determine the torsional stiffness; a process which requires expensive equipment and more importantly employee time to set-up and run. The torsional coupling lumped characteristics, such as torsional- and flexural stiffness, as well as natural frequencies are important for design of the entire power system and have to be as precise as possible. In this work, we have developed an accurate modeling framework for determining these parameters based on a full 3-D finite element model and model-order reduction procedure. Developed methodology was validated by available experimental data from one of the leading manufacturers of torsional couplings.