To provide a theoretical basis for metal honeycombs being used as buffering and crashworthy structures in a lunar lander system, this paper investigates the energy absorption properties of hexagonal metal honeycombs, and the size optimisation of the metal honeycomb energy absorber is performed by using response surface method (RSM). Specific energy absorption (SEA) is set as the design objective; the cell length and foil thickness of the metal honeycombs are optimised, while the applied mean crash load is set to not exceed allowable limits. The results demonstrate that this method is effective in solving crashworthiness design optimisation problems. Besides the design optimisation, parametric studies are carried out to investigate the influences of foil thickness and cell length on the metal honeycombs’ crash performances. The pre-processing software Patran is used to build up the finite element models and the explicit solver LS-DYNA is employed to perform the crashworthiness analyses.

This paper presents a geometric approach for design and synthesis of deployable/foldable single loop mechanisms with pure revolute joints. The basic kinematic chains with symmetric mobility are first synthesized, and an intuitive geometric method is proposed for the mobility analysis of these kinematic chains. The deployable/foldable single loop mechanisms can be regarded as a combination of the basic kinematic chains with nontrivial mobility intersection, under this approach, the 5R to 8R single loop mechanisms with symmetric mobility are synthesized systematically. The method for determining the positions of the joint axes on polyhedral links is also proposed, so that the mechanism can be fully deployed or fully folded without suffering from physical interference. Under this framework, a class of novel deployable/foldable single loop mechanisms is developed. The computer-aided design models for typical examples are built to illustrate their feasibility.

A deployment analysis and experimental study of a novel modular deployable truss structure for deploying and supporting a 28-m-long satellite synthetic aperture radar antenna is presented. Analysis of kinematics and singularity identified four types of singularity configurations. Singularity decoupling analysis indicates that two singularities can occur in the end phase of deployment and prevent complete deployment. A cubic polynomial deployment control strategy and an eccentric shaft design method are suggested to facilitate smooth deployment of the antenna modular deployable truss structure without encountering singularities. The proposed equivalent dynamic analysis method for forecasting driving force shows that the impact of increasing the number of modules is low for drive mechanism A but high for drive mechanism B. Scale model deployment experiments prove that the presented design scheme and deployment analysis theory are feasible. The proposed research can be applied to other large-scale satellite synthetic aperture radar antennas.

This article proposes a novel soft pneumatic actuator inspired by the segmented structure of earthworms. The actuator adopts a new structure of free bottom to eliminate the constraint of the bottom and enlarge the bending capacity of the actuator. Through simulation, it is found that the new actuator improves the bending angle by 20% and output force by 40% compared with traditional actuator. Moreover, key parameters of the actuator are analyzed to acquire their effect on bending angle and bending linearity. A guideline for the design and optimization of the actuator is proposed. To validate the simulation results, we build up a test platform to test bending angle and output force of the actuators, the results shows that errors between the simulation and the test remained in the limit of about 10%. Finally, a three-jaw soft gripper is fabricated and its grasping strategy is studied. The quantitative analysis shows its excellent adaptability and load capacity.