Membrane Space Structures Research Articles

Configuration Design and Verification of Shear Compliant Border in Space Membrane Structure.

To solve the non-uniformity of stress in space membrane structure and the lack of shear compliant border configuration design method, shear compliant borders are designed, optimized, and verified in terms of configuration. Firstly, an orthotropic model of the borders is built by combining Hill and Christensen-Lo composite material models. Secondly, a finite element form-finding method is put forward by establishing rectangular and cylindrical coordinates in different areas. The configuration of borders is obtained and the influence of the borders on the edge of the membrane is 0.23%, which means that the borders are compatible with the existing tensegrity systems, especially the tensioning components and the cable sleeves. Thirdly, simulation verifies that borders can cut the spread of shear stress and improve the stress uniformity in membrane structure. The maximum stress in the membrane effective area is decreased by 35.6% and the stress uniformity is improved by 30.5%. Finally, a membrane extension experiment is committed to compare the flatness of membrane surface under shear stress with and without shear compliant borders. The borders decrease the increment speed of flatness by 58.1%, which verifies the amelioration of stress uniformity. The shear compliant border configuration design method provides a reference for space membrane structure stress-uniform design.

Upper-bound vibration response spectrum computation for deployable membrane structures with uncertainty effects

Real-time monitoring technology is essential for establishing a control technology for large-sized membrane space structures. However, numerous measurement points are necessary to capture the maximum vibration response, which renders the real-time monitoring technology impractical. Thus, this study proposed an upper-bound vibration spectrum computation approach using a few measurement points samples on a deployable membrane structure. The proposed method exhibits characteristics of applying the standardized upper-bound spectrum, including uncertainty effects for the computations. The experiment results indicated that the upper-bound spectrum calculated from only 30 measured data points appropriately covered the measured spectra, thus confirming the effectiveness of the proposed method.

Placement optimization of elastic spacers for multi-layer space membrane structure

In recent years, there has been a growing interest in the dynamics of space membrane structures. However, existing research primarily focuses on single-layer membrane structures, leaving a significant research gap in the study of multi-layer structures with elastic spacers. To address this gap, this paper studies the dynamics and interlayer spacing accuracy of multi-layer membrane structures with elastic spacers. Specifically, the research focuses on the placement optimization of elastic spacers. A novel optimization criterion for the elastic spacers has been proposed, and the Particle Swarm Optimizer (PSO) algorithm has been utilized to calculate the optimal spacers positions. Results show that optimally placed elastic spacers can eliminate the crossing modes and improve the interlayer spacing accuracy during vibration.

Form-finding analysis and optimization of cable membrane structure based on iterative correction of tension process

The current form-finding analysis of cable membrane structures does not consider the actual tensioning process, thus leading to a difference between the form-finding prestressed and tensioning working states. It will affect the morphology accuracy of membrane structures in use, especially in the field of space structures. This work proposes a form-finding optimization method based on the iterative correction of the tensioning process, which considers membrane stress and edge shape optimizations in order. The method focuses on two evaluation indices: the average membrane stress difference and the root mean square (RMS) of the position difference of the edge cables. This sequential optimization analysis is illustrated based on the examples of a sunshade structure for aerospace applications. The results show that these design requirements on the two evaluation indices can be satisfied after one membrane stress optimization and one edge shape optimization. Subsequently, the influence of the seams on the optimization analysis of tensile cable membranes is also investigated. Although seams increase the inhomogeneity of the membrane stress and edge shape difference, the proposed optimization framework based on the iterative correction of the tension process can still ensure that the design requirement can be satisfied. The work in this paper could form the basis for a high-precision study of tensile membrane structures in space.

Simulation of membrane deployment accounting for the nonlinear crease effect based on absolute nodal coordinate formulation

With the advantages of lightweight and high stowing efficiency, the origami membrane has a broad application prospect in the space structure. As an improvement of the existing deployment simulations, the behavior of crease is considered and both static and dynamic simulation are conducted in this paper. The origami membrane is modeled as a flexible multibody system and its deployment is simulated based on the absolute nodal coordinate formulation. The nonlinear effect of the crease to resist deployment is integrated into the multibody system via the virtual work principle. The facet is modeled by the thin shell element and the crease is constructed as a nonlinear torsional spring with specific position and gradient constraints. The behavior of the crease is parameterized based on the experimental data. The modeling approach is verified by the numerical/experimental reference of the Z-folding structure in the existing literature. For the multi-crease origami membrane model considering the crease effect, a form-finding method to obtain the initial configuration of the flexible origami is proposed based on the principle of minimum potential energy. The deployment of the classical Miura-ori unit membrane structure is analyzed. The magnitude of driving force is estimated based on the force analysis of rigid deployment. Based on the simulation result of flexible deployment, the driving force is planned to achieve a stable deployment with a constant increase speed in the deployment ratio. This work is expected to provide a reference for the design of space membrane structure, the estimation of driving force, and optimizing the deployment strategy of an origami membrane.

Attitude control of spin-type space membrane structures using electromagnetic force in earth orbit

This research proposes a novel attitude control method for a membrane structure that uses electromagnetic torque while in Earth orbit. A spin-type membrane structure with a satellite’s body at its center is lightweight and highly compactible, enabling the realization of systems that require a large surface area. The attitude control of such a structure poses an issue because of a relatively large angular momentum of the membrane, requiring a large torque to shorten attitude control duration. Moreover, application of this torque to both the body and membrane is desired to prevent vibration on the membrane. A typical method using reaction wheels and thrusters applies a relatively large torque only to the body, which requires propellant consumption. Another method using solar radiation pressure applies torque only to the membrane, resulting in a weak torque. Thus, conventional methods cannot achieve a sufficiently large torque applied to both the body and membrane without extraneous propellant consumption. In the proposed magnetic attitude control method, the electric current flowing along the edge of the membrane and the magnetic torquers in the body interact with the Earth’s geomagnetic field and generate a large, controllable electromagnetic torque applied to both the body and membrane, which enables a large torque without consuming propellant. This research evaluates the performance of the proposed method in terms of the attitude maneuverability and vibration of the membrane using numerical simulations. Specifically, this research investigates the effects of the electric current, spin rate, and orbit inclination, which are related to the strength and direction of the electromagnetic torque. A dynamics model of the numerical simulations is derived from the multi-particle method. The numerical simulations reveal that the proposed method induces a larger torque compared with that by solar radiation pressure, improving maneuverability. This maneuverability is related to the electric current intensity and the orbit inclination. The vibration caused on the membrane during the attitude control is small; the maximum amplitude is only 3.1% of the membrane size. This amplitude decreases as spin rate increases because of geometric stiffness. Based on the results, this research concludes that the proposed method is technically feasible and contributes to the actualization of a large membrane structure.

Basic Mechanical Properties of Two-Dimensional Membrane Structures with Flexible Devices under Tensile Loads

This paper focused on the deformation and stress distribution as the basic mechanical properties of two-dimensional membrane space structures with flexible devices under tensile loads to improve surface flatness as the structural performance of the membrane structures. Finite element analyses of a square membrane with a square device under tensile loads in the diagonal direction using solid elements were performed to examine the stress concentration. Two models as the normal model and the device-inclined model with different configurations for attaching a device were investigated. Numerical results showed that the center of the membrane was deformed on the opposite side of the surface with a device attached in analysis models. The maximum displacement of the center of the membrane and the maximum stress around the device edge in the device-inclined model were smaller than in the normal model and the stress concentration occurred at the corners of the device in the normal model. Moreover, the results for different thicknesses of the device and membrane indicated the maximum deformation occurred when the thicknesses of the device and membrane were almost the same. Finally, the basic mechanical properties have been discussed.

Deployment behavior of planar gossamer space structures made of plain-woven textile

Multifunctional membrane space structures have been developed in the past to realize solar arrays, array antennas, and other applications. However, the deployment of a folded membrane often requires fluctuating forces with high peaks, caused by the stiffness of the crease lines. This study proposes the use of a plain-woven textile as the base membrane for the planar deployment structures primarily because of its high packaging efficiency. The deployment forces required for the folded plain-woven textile structures to be employed in future space applications are experimentally measured. The deployment forces are compared between the proposed textile structures and the conventional film-based membranes to characterize the deployment behavior of the textile structures. Two types of experiments are conducted in this study for the one-dimensional deployment of v-folded membranes and the two-dimensional deployment of quarter Flasher origami structures, respectively. The advantages presented by the deployable textiles are as follows: (i) they require smaller and smoother deployment forces, and (ii) they are insensitive to imperfect boundary conditions. These features are important for the reliable deployment of future space structures.

Compact Packaging of Planar Gossamer Space Structures Using Textile Membranes

This paper clarifies the mechanism of significantly improved compact storage of membrane space structures where plain-woven textiles are used as the base membrane. Membrane space structures can be multifunctional by attaching various thin-film devices onto their surface; however, the non-negligible thickness of the devices should be accommodated to achieve compact storage. In this study, small scale models made of membranes with dummy thin-film devices are stored to show two significant aspects. Firstly, that textile membranes can be stored more compactly and uniformly than polymer films, because of the movement of layers caused by the flexibility of the textile. Secondly, that the locations of the movement between membrane layers to absorb thickness effect differ depending on the fiber orientation of the textile.

Electromagnetic Deployment of a Membrane Structure in LEO

Space membrane structures provide a large surface area while being lightweight and efficiently storable. Two types of deployment methods have already been demonstrated: using booms or centrifugal force. However, it is difficult to control the deployment force in high frequency, and the associated impact and vibration to the membrane structures pose risks for mission failure. This study proposes a new deployment method using electromagnetic force. This method flows electrical current on the membrane to deploy via electromagnetic force. While electromagnetic force can be manipulated by changing the electrical current, electromagnetic force is also affected by the membrane deployment behavior. Since electromagnetic force is weak, the influence of environmental forces on the deployment behavior becomes larger than in the previous methods. Thus, to achieve consistent electromagnetic force control, the deployment behavior should be understood. This study aims to reveal the possibility of deployment using the proposed method and investigate the deployment behavior in LEO with numerical simulation based on the multi-particle method. From the results, this research finds that the membrane deployment with the proposed method can be divided into three phases. Furthermore, this study reveals the relationship between the deployment behavior and electromagnetic and environmental forces in LEO.

Dynamic modeling for foldable origami space membrane structure with contact-impact during deployment

The dynamic modeling for the foldable origami space membrane structure considering contact-impact during the deployment is studied in this paper. The membrane is discretized using the triangular elements of the Absolute Nodal Coordinate Formulation (ANCF), and the stress–strain relationship of the membrane is determined based on the Stiffness Reduction Model (SRM). A mixed method is proposed for the frictionless contact problem by combining the membrane surface-to-surface (STS) contact elements with the membrane node-to-surface (NTS) contact elements to improve precision. Compared with the traditional STS contact elements, the mixed method can effectively avoid mutual penetration of the element boundaries, especially for the foldable origami membrane structures undergoing overall motions. The penalty method is adopted to enforce the nonpenetration condition. Moreover, special constraints are built for the fold lines, and then the dynamic equations of the membrane multibody system considering the damping effect are formulated. The dynamic deployment procedure of a leaf-in origami membrane structure with contact-impact is performed employing this present mixed method. The results demonstrate the effectiveness and superiority of the presented mixed method in the solution of the complicated contact problem, and the influence of the contact-impact on the dynamic performance is analyzed.

Multiple-model switching control for vibration suppression of planar membrane structures

Membrane space structures have received widespread attention because of their small packaging volume and low mass. However, because membranes are very flexible and lightly damped, vibration suppression in membrane structures is very difficult. The objective of this study was to solve this problem. The first part of this article describes the influence of wrinkling in a membrane structure on the structure’s vibration characteristics. On this basis, the vibration deformations of a wrinkled square membrane structure were derived from the dynamic equations, and the correctness of this vibration model was verified by numerical simulation and experiment. A multi-model system is proposed to simulate the dynamic response of a membrane structure under different boundary conditions. In combination with the drive system, a multi-model switching control method based on adaptive and proportional–integral–derivative control is proposed. Under the initial disturbance, when the vibration amplitude dropped below 0.01 mm, the vibration duration was reduced to 2.96 s, compared with the duration of 12.37 s without control. The duration was shortened by approximately 39.7%, compared with the duration of 4.91 s achieved by the traditional proportional–integral–derivative control method, and by approximately 15.9% compared with the 3.52 s achieved by the out-plane control method. When there were multiple disturbances and the proposed method was used, the boundary displacement loadings did not increase when a certain value was exceeded. This prevented the breaking of the membrane by overstretching and provides a theoretical foundation for setting the initial pre-stress values.

Active Shape Control of Spinning Membrane Space Structures and Its Application to Solar Sailing

Active Shape Control of Spinning Membrane Space Structures and Its Application to Solar Sailing

Comparative finite element and experimental analysis of a quasi-static inflation of a thin deployable membrane space structure

The deployment of a thin, one-segment, large membrane space structure is examined by the means of a real time quasi-static inflation experiment with photogrammetry and finite element analysis with the explicit and implicit schemes applied to control volume, corpuscular and arbitrary Lagrangian-Eulerian inflation methods. The numerical solutions comparison is based on mesh size, energy ratio, number of particles, bleed-through leak coefficient, fluid pressure - surface depth stiffness coupling, accuracy and computational efficiency. An optimization of the number of particles and minimization of the bleed-through effects is effectively implemented in corpuscular and ALE approaches. The corpuscular and arbitrary Lagrangian-Eulerian are found to be most resembling the experimental results in the dynamic shape changes and the time history of the gas properties, but computationally expensive. The control volume, although computationally efficient, is lacking the adequate fluid-structure interaction, thus less accurately recreating the overall dynamics of the morphing surface. Only 0.2%–1.75% and 0.5%–2.5% difference is observed between the experimental, analytical and finite element inflation results respectively.

Decentralized adaptive fuzzy vibration control of smart gossamer space structure

Gossamer space structures technology have gained widely applications in space missions. However, the vibration problem is a great challenge which makes the technology complicated. The overall motivation of this work is to develop a vibration control system for gossamer space structures. In this study, a space membrane structure with piezoelectric stack actuators bracketed on its support frame is considered. First, the description of the smart space membrane structure and its dynamic model are presented. Then, a decentralized adaptive fuzzy control method is developed to control the structure vibration. Finally, experimental system is built up, and two vibration control experiment cases are carried out to verify the proposed control method. Experimental results demonstrate that the proposed control method is more effective than the fuzzy control method.

Wrinkling analysis and control of rectangular space membrane

Wrinkling, a common phenomenon found in space membrane structures, is the main factor affecting the performance, stability, and dynamic characteristics of these membrane structures. This article presents an active control method to improve the surface accuracy of membrane structures. A model of a thin rectangular membrane subjects to uniaxial uniform tensile stress is discussed. Initially, the relationship between the out-of-plane deformation of the wrinkles and the boundary conditions is built with the Föppl–Von Karman plate theory by introducing the slow varying Fourier series. Because vertical tensions perpendicular to the direction of the initial wrinkles are necessary to reduce these wrinkles, reasonable locations and magnitudes of these tensions are the key problems. The finite element method and variational principle method are used to solve this issue. Finally, a manufacturing error is added to the model as an initial defect, and the robustness of the controller is verified. Simulation results show that wrinkles are reduced quickly and effectively with the proposed method.

Evaluation of transient response of spinning solar sail with flexible membrane by eigenfunction analysis and continuum analysis

This study evaluates the transient response of large spinning membrane structures in space – especially spinning solar sails – by two different methods. A flexible sail membrane is easily deformed when a spacecraft changes its attitude, such as when using thrusters, and the control response including membrane vibration must be estimated in advance of operation. In order to estimate the motion of the membrane, numerical simulations using a multi-particle model (MPM) are conducted, where the membrane is modeled with masses, spring, and dampers. Usually, force propagation is calculated directly in this model and the position and velocity of each particle represent the membrane motion, which is referred to as a continuum analysis in this study. This method is useful for the analysis of membrane vibration because it replaces the complex dynamics with simple equations of motion. However, the computational cost is high and the calculations require a considerable amount of time. This study introduces an eigenfunction analysis to solve this problem. In this method, natural vibration modes and natural frequencies for the entire spacecraft are derived and used for dynamics computation, which reduces the computational cost dramatically compared to the conventional continuum analysis. In this study, the transient response of a spinning solar sail is analyzed using both methods, and the advantages and disadvantages are discussed. It is shown that the eigenfunction analysis provides a suitable method for acquiring approximate solutions in a very low computation time.

Conceptual model study using origami for membrane space structures - a perspective of origami-based engineering

Conceptual model study using origami for membrane space structures - a perspective of origami-based engineering

S192012 膜面宇宙構造物用コンベックステープの展開挙動に関する研究([S192-01]宇宙システムに関する実践的解決と知見の汎用化(1))

S192012 膜面宇宙構造物用コンベックステープの展開挙動に関する研究([S192-01]宇宙システムに関する実践的解決と知見の汎用化(1))

P11 ブーム剛性の変化を考慮した多粒子法による膜面構造物の展開解析(ALSSポスターセッション/アピールタイム(2))

P11 ブーム剛性の変化を考慮した多粒子法による膜面構造物の展開解析(ALSSポスターセッション/アピールタイム(2))