Dynamic topology optimization of flexible multibody systems

Flexible multibody system (FMBS) refers to a mechanical system, which consists of flexible components and kinematic pairs, and undergoes both overall motions and deformations. FMBS serves as a useful dynamic model for many advanced industrial products, such as flexible robots, helicopter rotors and deployable space antennas. Traditionally, the design of flexible components in an FMBS mainly relies on the trial-and-error method, which is time-consuming and cannot guarantee the best design. In addition, the optimization design of the flexible components in an FMBS usually uses a component-based approach without accounting for the interaction between a component to be optimized and the FMBS of concern. Yet, when a component gets more and more flexible, the interaction between the component and the FMBS plays a nonnegligible role in optimization and requires the FMBS-based optimization. This feature article presents the basic ideas and methods for the dynamic topology optimization of an FMBS mainly based on the studies of the authors over the past decade. The article focuses on four emerging topology optimization problems of an FMBS as follows, (i) topology optimization of dynamic responses and dynamic characteristics, (ii) fully coupled and weakly coupled optimizations, (iii) topology optimization of time-varying systems, and (iv) optimization designs and prototype tests of flexible robots. Together with concluding remarks, the article addresses some open problems of the dynamic topology optimization of an FMBS for future researches.