Modeling inflatable fabric with undevelopable surfaces by motion folding method

Abstract

At present, most space inflatable structures are composed of flexible inflatable fabrics with complex undevelopable surfaces. It is difficult to establish a multi-dimensional folding model for this type of structure. To solve this key technical problem, the motion folding method is proposed in this study. First, a finite element model with an original three-dimensional surface was flattened with a fluid structure interaction algorithm. Second, the flattened surface was folded based on the prescribed motion of the node groups, and the final folding model was obtained. The fold modeling process of this methodology was consistent with the actual folding processes. Because the mapping relationship between the original finite element model and the final folding model was unchanged, the initial stress was used to modify the model errors during folding process of motion folding method. The folding model of an inflatable aerodynamic decelerator, which could not be established using existing folding methods, was established by using motion folding method. The folding model of the inflatable aerodynamic decelerator showed that the motion folding method could achieve multi-dimensional folding and a high spatial compression rate. The stability and regularity of the inflatable aerodynamic decelerator numerical inflation process and the consistency of the inflated and design shapes indicated the reliability, applicability, and feasibility of the motion folding method. The study results could provide a reference for modeling complex inflatable fabrics and promote the numerical study of inflatable fabrics.

Investigation on the Folding Mode and Deployment Process of an Inflatable Boarding Platform for the Marine Emergency Evacuation System

“…Yu et al [17] used the control volume method to simulate the inflation process of Z-type folded space inflatable structure, control the different deployment constraints, and determine the effective constraint range of the structure. Aiming at the inflatable structure of flexible fabric, Zhao et al [18] used the method of motion folding to establish the folding model of inflatable aerodynamic reducer which cannot be established by the existing folding method, and then realized multi-dimensional folding. In the above cases, the experimental objects are mostly small airbags, which are generally simple in shape, have a small model airway volume, and have a short inflation time.…”