Stability Analysis Of Cable-suspended Dome Under Wind And Snow Loads

In recent years,cable-suspended domes have been widely used all over the world due to their high structural efficiency,excellent architectural effect.They are very sensitive to non-uniform wind and snow loads.In recent years,good results have been achieved in the study of snow-induced disaster mechanism of long-span spatial structures.But the research that the influence of non-uniform wind and snow loads on cable-suspended dome is still few.In this paper,ANSYS finite element model of K6 cable-suspended dome is established.In snow load stability analysis,selection of snow load according to relevant codes.The ratio of prestressing force is determined by the method of the control area of the strut.The prestressing amplitude is determined by the criterion of equal radial displacement of the support.Six load distribution forms are obtained by combination the distribution forms of full span,half span,outermost-two-rings half span and uniform,non-uniform.In wind load stability analysis,wind speed time history was generated with the MATLAB Software,based on AR(Auto Regressive)model theory,considering the characteristics and spatial correlation of mean wind and fluctuating wind.The static and dynamic stability of cable-suspended domes reticulated shells under snow load and wind-snow load are systematically analyzed.The analysis combined with B-R(Budiansky-Roth)criterion and cable relaxation.The results show that: the stability bearing capacity of form that non-uniform distribution of half-span is minimum.The structure have the largest stability bearing capacity when loads are distributed evenly over the outer two rings of half spans.Comparing with the results of K6 single-layer spherical reticulated shell structure,the stability bearing capacity of K6 cable-suspended dome structure increases the most in the form of uniformly distributed snow load on the outer two rings and half spans,while increases the least in the form of full-span snow load.The critical wind speed of structural dynamic instability is 83m/s when without snow load.When snow load in the non-uniform distribution of half-span,uniformly distributed of outer two rings and the non-uniform distribution of outer two rings,the critical wind speed is the minimum that is 84m/s,which is close to the no snow load.It is shown that for reticulated shells with small rise-span ratio,wind-induced instability of reticulated shells is beneficial when snow loads are considered together.When cable-suspended dome under wind load,the brace inclines at the instability point and the cable stress decreases.It can be seen that the cable basically withdraws from work under wind suction,and the latticed shell with chord supports is sensitive to wind suction.