Mechanical Analysis Of Chord-Supported Domes With Continuous Cables Under Heterogeneous And Homogeneous Snow Loads

The chord-supported dome structure is a composite space structure with rigid singlelayer reticulated shell and flexible tensegrity at the upper part.The structure has the advantages of large stiffness and strong stability.Researchers have carried out many researches on it,but there are still some shortcomings in the chord supported dome structure.In the simulation of the chordal dome structure,most of the two nodes discontinuous cable elements are used to deal with the structure.The discontinuous cable elements make great differences in the internal forces of the structure,and ignore the influence of friction,resulting in the inner loss of the structure.This article in string a dome structure exerts a complete and independent continuous unit,the static,stability and dynamic analysis.First of all,in this paper,based on the theory of continuous line units,unit was deduced stress stiffness matrix and mass matrix,damping matrix.Using FORTRAN education-the algorithm into the subroutine.Secondly,according to the literature and specifications to determine the snow load distribution of different forms,and consider the snow load of non uniform,snow load can be divided into the whole cross,half across different,the two and a half ring and central half cross under the uniform and non uniform snow load.On the basis of considering the friction and does not take into account the friction divides into two aspects,the dome for string,the outer ring line respectively applying continuous cable for static analysis research.Decorate a continuous cable on the structure will produce larger vertical displacement,but also stress equilibrium structure of strop unit.Snow load of non-uniform distribution and the inner ring line location or unit of inner and outer cable layout continuous cable have bigger influence on the structure.Then,select a half across different,the two and a half ring and central half cross under the uniform and non uniform snow load,applying continuous cable to the structure analysis of the structure stability analysis.Half span structure under snow load limit bearing capacity is highest,followed by the two and a half ring across the snow load,outside central half across the lowest structural ultimate bearing capacity under snow load.Snow load of non uniform and layout of the inner and outer cable for cable unit had a greater influence on the bearing capacity of structure.Structural parameters of rise-span ratio on structure limit bearing capacity increases,the biggest height of poles and ring turns contribution to structural ultimate bearing capacity is small.Finally,the natural vibration characteristics of the structure under different loads and structural parameters are analyzed based on the friction action and the different arrangement of the continuous cable elements.Under different loads,the arrangement of continuous cable elements has little influence,but the structure frequency decreases with the increase of load.Under different parameters,the arrangement of continuous cable elements does not affect the change of the overall trend of the natural vibration frequency of the structure,but the arrangement of continuous cable elements under the parameters of the ratio of vector to span and the number of loops greatly changes the frequency of the structure.In conclusion,snow load heterogeneity can reduce the stiffness and stability of the chord-supported dome structure.The stress amplitude and stability of the loop cable element of the structure with continuous cable element are lower than that of the discontinuous cable element,but the continuous cable element keeps the balance of the loop cable internal force and has little influence on the dynamic characteristics of the structure.Therefore,the continuous cable element is suitable for the structure of the chord-supported dome.The safety and reliability of the structure can be improved by using the continuous cable element design and considering the influence of the uneven snow load in practical engineering.