Research On A Novel Deployable X-cable Dome:System Exploitation,Morphological And Mechanical Analysis

Cable dome structure has been in the process of continuous improvement and innovation since it came into being.The traditional cable dome structure has poor overall stability,complex construction technology and difficulty in forming,so there are few engineering examples.With the increasing maturity of spatial structure calculation theory,hybrid structures have begun to rise and develop,and the application of deployable structures in roof systems has become more and more extensive.In view of the feature that the deployable structure can effectively improve the construction efficiency of the structure,the research on the novel deployable cable dome structure which introduces the deployable structure has important research significance.In this paper,the scissor strut is introduced into the sunflower-patterned cable dome structure,and a deployable X-cable dome structure is developed.First,the structure formfinding was completed,and the initial prestress distribution law of the structure under different parameters was explored;secondly,based on the self-compiled vector finite element program,the mechanical properties of the novel structure and the tension forming analysis were carried out in depth;finally,the scale model is introduced and conclusions with practical application value are summarized.The specific research content is as follows:First of all,this paper conducts a morphological analysis study of the deployable X-cable dome.On the basis of completing the structure form finding,the calculation method based on the balance matrix theory and the joint balance theory to solve the initial prestress distribution is explained.Under the parameters,the change law of the proportional relationship of the initial prestress distribution of the structure is analyzed and summarized.It is pointed out that the selfstress mode must be positive and the mechanisms mode equals to zero,which means the structures belong to the statically indeterminate and movingly determinate.The dynamic characteristics of the structure are explored through finite element simulation,and the natural frequency and mode of the structure are solved.The results show that the natural frequencies of the structure are densely distributed and the first order frequency is small,which proves that the structure has good stiffness and strong symmetry.Secondly,the mechanical model of the extensible cable dome is established in this paper.A simplified algorithm based on force method and superposition principle is proposed,and the reliability and effectiveness of this method are verified by comparing the calculated results with the numerical simulation results.Based on the vector finite element method,the whole static response of the structure under uniform load of full span was solved,and the results were compared with those of herringbone ribbed cable dome and sunflower-patterned cable dome.The analysis shows that the bearing capacity and stability of the extensible cable dome are better than the others,which proved that the novel system has good mechanical properties.Thirdly,this paper simulates the forming process of the deployable X-cable dome.Based on the vector finite element method,the inverse analysis method is adopted,starting from the initial prestressed state of the structure,the corresponding tensioned cables are dismantled,the zero stress state configuration of the structure is solved,and on this basis,the change of internal force and configuration of the cable bar during the tensioning process of the diagonal cable of the outer ring is tracked.The simulation results show that the configuration changes of the structure are symmetrical during the whole process.When the tension reaches 1.7 tension steps,the structure basically takes shape.Thereafter,the joint height and the internal forces of the cable and bar of the structure all change linearly with the tension steps,and there is no sudden change or trend change.Finally,a scale model of the the deployable X-cable dome is realized.The detailed nodes and assembly process of the model are designed,and the working mechanism of the new structure to improve the construction efficiency is revealed.In addition,a construction forming scheme of the whole ground assembly,the whole synchronous lifting and the tension outer ring cable is put forward,which provides suggestions and references for the practical application of the structure in the future.