A multi-dimensional morphing wing skeleton mechanism is proposed with double-sided triangular pyramid units, which can realize continuous variable span-wise bend, span-wise twist, and sweep. A lockable morphing unit is designed, and its mechanism/structure characteristics, degree of freedom, and the deformable function of its deformable wing skeleton mechanism are analyzed. One kind of flexible skin is proposed to meet the performance requirements, consisting of an internal metastructure and a flexible surface bonded on both sides. The morphing wing skeleton mechanism and the equivalent treated metastructure flexible skin are then combined. Subsequently, a two-way fluid–structure interaction analysis is conducted to investigate the influence of aerodynamic loads on the flexible skin and skeleton mechanism in different deformation states, including the influence of structural passive deformation on the aerodynamic characteristics of the morphing wing. The computational fluid dynamics method is employed to analyze the aerodynamic characteristics of the morphing wing in its initial state, as well as in three deformation states, and to study its aerodynamic performance in different flight environments.

A symmetric, double-tripod multiloop mechanism (DTMLM), intended for grabbing objects in outerspace, is the subject of this article. Actuation modes are analyzed while introducing a novel tool applicable to space mechanisms. The key issue here lies in establishing the criteria for selecting the optimum mode from multiple actuation possibilities. The evaluation procedure includes generalized-force values, power requirement, and actuation-strategy models, along with their optimization. Accordingly, the optimization procedure targets the mode(s) with 1) uniformity of generalized-force distribution, 2) uniformity of power-requirement distribution, and 3) the fewest working actuators in a given maneuver. In this way, a rather complex problem is formulated in a simple manner, whereby the optimum actuation mode is found by list-lookup, from a reduced number of candidates. The DTMLM, which carries three compound hinges plus three prismatic, and six revolute joints, has three degrees of freedom. To analyze the actuation modes of the mechanism, the dynamics model of the DTMLM is established; as well, five representative modes are selected from 84 possibilities. It turns out that the 3R-type (three revolute actuators) shows a uniform power-requirement distribution among the three actuators in the bending motion mode; in the 3P-type (three prismatic actuators), one single actuator is operational, and hence, takes all the load. Thus, the 3R-type is the best from the power-distribution viewpoint, thereby providing strong power support, but complex from the actuation-strategy viewpoint, as illustrated in the article. Simulation results and prototype experiments of the DTMLM are reported, thereby verifying the analysis results.