Structural optimization of flexible components in a flexible multibody system modeled via ANCF

• Dynamic response structural optimization of a flexible multibody system is studied.
• The flexible multibody system subject to large deformation is modeled via ANCF.
• The ESL method is reevaluated to optimize large-scale flexible multibody systems.
• A multipoint contact detection method is proposed for a robot's grasping process.

The paper presents how to optimize the flexible components in a flexible multibody system undergoing both large overall motion and large deformation by using the Absolute Nodal Coordinate Formulation (ANCF) and the equivalent static load (ESL) method. Before the structural optimization, the flexible multibody system is modeled via ANCF first so as to describe the coupled overall motion and large deformation accurately. During the structural optimization, the elastic deformation of the flexible component to be optimized is split from the overall motion of the flexible component, and then the equivalent static loads are determined by using the ESL method such that the structural optimization of nonlinear dynamic response can be transformed into a static one. In addition, the nonlinear interior point method is adopted to solve the corresponding structural optimization problem of nonlinear static response. The paper gives three numerical examples to validate the above optimization procedure. The final example of optimizing the arms in a rigid-flexible grasping robot shows that the proposed optimization procedure enables one to deal with realistic engineering systems.