Design And Analysis For Umbrella-type Deployable Mechanism Based On The Structure Of Spider Web

During the construction of the aerospace project,due to the space constraints of the launch vehicle,many aerospace equipment cannot enter the space in full state at work.With the development and advancement of aerospace technology,it has the advantages of small footprint and cost saving.The exhibition organization has received unprecedented attention and research,and has been widely applied in practice.The expandable mechanism can expand and close the mechanism according to the change of its working state,thereby improving the efficiency of space use and maintaining a stable structural state to withstand a certain load.Compared with other kinds of expandable mechanisms,the umbrella-shaped exhibitable mechanism has a higher precision requirement,but it has a convenient unfolding process and an effective carrying capacity.In order to make the umbrella-shaped expandable mechanism have more effective carrying capacity,this paper designs a kind of plane four according to the theory and method of bionics and mechanism design,through the research and analysis of the shape and bearing capacity of spider web structure.The rod crank slider mechanism is an umbrella-shaped expandable mechanism of the expandable unit,which combines the stray force characteristics of the spider web and has high bearing performance.The research content of this paper includes the following aspects:Firstly,based on the theory and method of bionics,the shape and unit structure of spider web structure are extracted,and a simplified spider web structure model is proposed.A planar four-bar crank slider is proposed according to the structural unit of spider web structure model.The expandable unit of the structure designs an umbrella-shaped expandable mechanism that can be effectively deployed and contracted in the space based on the expandable unit.Secondly,through the analysis of the bearing characteristics of the spider web structure,two variables affecting the structural strength of the spider web were determined.Based on the simplified model of the spider web structure,its three-dimensional model is established,and it is statically analyzed by Ansys Workbench to obtain the stress point of the most vulnerable structure.Based on the force point,the optimization thread of the spider web structure is optimized by the optimization module of Ansys Workbench,and the optimized ratio of the wire-harvesting spacing is d1:d2:d3 =1:2.1:4;through the single-layer spider web The strength analysis of the rigid frame model shows that the mesh surface has a higher strength performance when the spider net model has a wire-harvesting angle of 7°.Then,based on the optimization results of the strength performance of the spider web structure model,the parameters of the umbrella-shaped expandable mechanism are designed to obtain the umbrella-shaped expandable mechanism model with the best strength performance.The Ansys Workbench is used to optimize the umbrella shape before and after optimization.The institutional model is simulated.The structure shows that when the same load is applied to the same position,the maximum stress value of the optimized umbrella-shaped expandable mechanism is smaller than that of the umbrella-shaped expandable mechanism before optimization,and the strength performance is effectively improved.Finally,according to the three-dimensional model of the umbrella-shaped expandable mechanism,the physical prototype is manufactured by 3D printing technology,and the assembly and debugging are completed.By controlling the movement of the slider in a single structural unit in the umbrella-shaped expandable mechanism,it is observed that the prototype has a good movement process of unfolding and folding,which proves that the umbrella-shaped expandable mechanism has effective mechanical properties and industrial manufacturing feasibility.