Research On Folding Modeling And Deployment Dynamics Of Inflatable Structure

The deployment dynamics of the inflatable structure determines its in-orbit deployment,but its in-orbit deployment characteristics testing is difficult and costly.When conducting ground tests,it is difficult to simulate the space environment due to ground tests,so numerical simulations are often used as inflatable structures Another means to develop dynamic characteristics research,the results can provide a basis for the design and optimization of inflatable structures,and folding modeling of inflatable structures is the key to numerical simulation.However,there is no suitable folding modeling method for non-expandable curved surfaces or complex forms of inflatable structures.To solve this problem,this paper proposes an improved reverse folding modeling method to analyze the folding and expansion of non-expandable curved surface inflatable structures.Expand the dynamic characteristics.First,on the basis of the reverse folding modeling method,this article loads the inflatable structure through a rigid body applying displacement,and obtains the folded model of the inflatable structure.At the same time,considering the effect of wall thickness on the bending rigidity of the structure,the element analysis model uses shell unit.The improved folding modeling method conforms to the stress situation of the inflatable structure during folding,and uses this method to establish a simple inflatable tube folding model to verify the correctness of the model.Secondly,using the improved model proposed in this paper,the non-expandable curved surface inflatable structure-airbag as the object,to study the impact of elastic modulus and wall thickness on the folding characteristics of the airbag,including crease stress,force comparison of different positions of the inflatable structure,The influence of elastic modulus and wall thickness on the folding characteristics is obtained.The results show that the thick-walled inflatable structure is prone to produce larger stress values on the inextensible curved surface during the folding process,and the high-modulus inflatable structure is more than the low-modulus inflatable structure.The resulting stress concentration is obvious.Finally,using the airbag folding model,the effects of elastic modulus,inflation structure size,and wall thickness on the deployment dynamics of the airbag,including deployment speed,deployment displacement,and stress comparison,were studied.The results showed that: The mark has a larger stress value,and the expansion is slow,and the greater the elastic modulus or the wall thickness,the greater the stress value at the location.Therefore,it is necessary to avoid more creases when the inflatable structure is folded;The unfolding characteristics have a significant impact.