Papers by Keyword: Deployable Structure

Abstract: The paper discusses seismic performance of deployable brace member as well as its application in single-story single-bay frame by using finite element method in OpenSees Navigator. Even though deployable structure has wide applications in engineering area, it is almost blank for earthquake (seismic) engineering. A finite element deployable brace model consisting two identical struts and a revolute joint is built in this paper. The model considers joint clearance and initial eccentricity to accord practical situation. Hysteresis analysis has been done on the brace model as well as its application. The results show deployable structure provides sufficient lateral stiffness and ductility. Strut eccentricity is the key factor affecting the capacity of the strut and buckling strength, while joint clearance also has influence on the strut capacity and energy dissipation.

Abstract: Deployable structures can provide a change in the geometric morphology of the envelope by contributing to making it adaptable to changing external climate factors, in order to improve the indoor climate performance of the building. They have the ability to transform themselves from a small, closed or stowed configuration to a much larger, open or deployed configuration being also known as erectable, expandable, extendible, developable or unfurlable structures. According to their structural system, deployable structures can be devided in four main groups: spatial bar structures consisting of hinged bars, foldable plate structures consisting of hinged plates, strut-cable (tensegrity) structures and membrane structures. In this paper a short review only on two of these groups of deployable structures for arhitectural applications will be presented.

Abstract: As the development of space structures is increasing fast, analysis on the characteristics of those deployable structures deserve to be paid enough attention to ensure a reliable deployment on orbit. For a deployable truss structure, more than one position can be chosen as the driving positions, especially when the structure has not only 1 degree of freedom (DOF), an available choice of the driving positions shows significant importance on the performance of the space deployable structure. This paper mainly deals with a planar deployable support truss structure for space antenna by means of the closed loop equations and the Kane equation to discuss the deployment characteristics by comparison of the driving torque needed over time. A full comparison of all the possible examples of deployment analysis results under different driving modes is presented. The results show the importance of the choice of driving movements and the design of parameters and also provide a useful reference to other related truss structures.

Abstract: The deployable structure of the ring truss have advantage properties, which can be used as an effective supporting structure of deployable antenna. The deployable experiment of ring truss antenna showed that there was asynchronous phenomenon at the course of the deployment. Dynamics theory including constraint equations and considering friction factor are built firstly. Then simulation is studied systematically for the deployment process of ring truss deployable antenna. At last, the conclusions are obtained that the friction insulted in tensile forces of the cable drive decrease and the asynchronous phenomenon in the process of the deployment. It will give some help to the design and manufacture of the ring truss antenna.

Abstract: Remote sensing satellites equipped with large synthetic aperture radar (SAR) can image the earth in all weather and lighting conditions. For high packaging efficiency in launch and precise configuration on orbit, deployable mechanisms are designed to deploy the large SAR antenna panels. For the two-panel antenna, a six-bar-linkage deployable driving mechanism is designed. According to the design, a parameterized dynamic model is built in ADAMS software with secondary development technology to obtain its dynamics characteristics through simulation analysis. To improve the dynamic characteristics and the precision of deployment design of experiments and optimizations were carried through in this paper.

Abstract: Virtual surface measurement is necessary to assist the actual measurement of large deployable space antenna structure. To realize a virtual surface measurement on this kind of structures, we take several steps to get the virtual measurement images. A virtual 3D model of the antenna structure and virtual hung system are constructed; virtual measure rules, coded marks and uncoded marks are also built up. The pinhole camera model is used to simulate the actual photogrammetric measurement tools. Through examples with OpenCV tools, the virtual measurement method is verified to be reasonable. Then different resolution images of perspective projections of the virtual measurement in virtual camera positions and orientations are obtained. Proper selections of the camera resolution and proper positions and orientations of the camera are found through virtual measurement experiments. Such results can be used in an actual photogrammetric measurement. The virtual measurement method can be used to reduce the attempt times and to assist the actual measurement with available photogrammetric measurement tools.

Abstract: Deployable Structures are generally those space structures being capable of turning from a folded and compact configuration into a predefined deployed configuration. These structures bear the loading in a deployed configuration. Scissor-type structures are one of the most complicated deployable structures, being stress-free in both deployed and folded configuration, but stresses could increase when explored deployment and perform a highly nonlinear behavior. There are mostly some defects and imperfections observed in fabricating such members and assembling the whole structure compared to the ideal model. The existence of these defects and geometric imperfections could influence the total or partial behavior of the structure. These imperfections could highly affect the structural deployability, the required force for deployment procedure and load bearing capacity of the deployed configuration. In the present study, the effect of member’s length imperfection due to inner, outer and a hybrid configuration of scissor-link Elements on the behavior of curved scissor-type structure are investigated.