Study On The Design And Application Of Tensegrity Membrane Structure

As a kind of lightweight,transparent and self-cleaning building material,building membrane material is not only used in conventional enclosure material,but also become a common building material in retractable structure.At present,there is a lack of coordination between the membrane material and the rigid members in the membrane structure.The retraction of the structure through the expansion and reception of the membrane material is the most convenient way to retract the structure,but there is also the problem that the membrane material is wrinkled and easy to be damaged.In order to solve the above problems,a new type of inflated membrane structures is proposed in this paper.While enhancing the synergistic effect of membrane materials and rigid components,as an retractable structure,it can avoid the wrinkles of membrane materials in the process of retracting the structure.In this paper,the theory and application research on the design of tensegrity membrane structure are carried out.The main contents are as follows:(1)A design scheme of tensegrity membrane structure is proposed,in which the skeleton is composed of the truss and the support between the truss,and the web cable is added between the upper and lower chords of the truss,and the membrane material is fixed outside the skeleton.The prestress of the membrane material and the skeleton is established by inflating the air bag composed of the membrane material.The airbag material serves as the enclosure member,and provides elastic support for the upper and lower chord members at the same time.Because the membrane material has stable geometric shape and certain geometric stiffness under the action of internal and external pressure difference,the purlin system in the traditional roof system is not needed.at the same time,the membrane material also provides elastic support for the upper and lower chord members,which enhances the synergistic effect of the membrane material and rigid members,so it has excellent structural performance.(2)The design scheme of the tensegrity membrane structure is studied theoretically,and the load effect result of the tensegrity membrane structure is obtained by using the simplified calculation and finite element analysis method.The calculation results show that the upper and lower chords of the truss in the tensegrity membrane structure will produce a certain bending moment under the tension of the membrane material,and the web cable can effectively reduce the bending moment and make the upper and lower chords mainly bear the axial force.The static characteristic of the truss in the tensegrity membrane structure is close to that of the traditional truss.Considering the prestress of membrane material,the modal analysis results of tensegrity membrane structure show that a certain amount of support is still needed between trusses to ensure the out-of-plane stiffness of a single truss in the skeleton.(3)According to the geometric characteristic that most of the membrane material of the whole tensioned membrane structure is arc-shaped,a simplified modeling method suitable for arc membrane material is proposed.In this method,two membrane elements tangent to the arc membrane material are used to simulate the force of the arc membrane material on the structural skeleton.The finite element analysis in this paper and the comparison with the calculation results in the literature show that the simplified method is more efficient on the premise of ensuring the same accuracy.(4)A unique retractable method suitable for the characteristics of the whole tensioned membrane structure is proposed and the environmental adaptability is studied.In the process of external force pulling the moving end of the tensegrity membrane structure to the fixed end,the retractable of the structure is realized through the change of the radius of curvature of the membrane material and the distance between the trusses.In the retractable process,there is not only the translation of the rigid structure but also the appropriate crimping of the membrane material,compared with the traditional retractable method.After the structure is fully opened,the space occupied by the rigid structure is smaller,and there is basically no wrinkle in the membrane material.On this basis,it is proposed to use the retractable characteristics of the tensegrity membrane structure to change the volume of the airbag to form a temperature adaptive system,and the parameter selection of the temperature adaptive system is analyzed by a numerical example.As a result,the goal of the design and application of tensegrity membrane structure is realized in this paper.The relevant results of this paper can be used as a reference for the design of tensegrity membrane structure or similar projects.