A Search Of Modeling-wind-pressure-reducing Method In Spatial Structures

Spatial structures have been vastly applied on various occasions as the flexibility of the interior space arrangement, yet this kind of structure is of its inherent shortcomings: the light mass, the large softness and also the small damping. Since it is still developing towards the direction of being more flexible, a consequence can be expected as that the sensitivity that the response of this kind of structures to wind loads will continue to increase, which makes the dominant effect of wind loads on designing such kind of structures be more significant day by day.In response to wind-induced damage on the structures, scholars and engineers have proposed a variety of theories and coping strategies, which have been carried out in the design of high-rise structures and bridges and have turned out being of good practice effect.But so far, the academia has not presented even one theory of reasonable maturity on wind-induced damage occurring on large-span spatial structures, which is reflected in the project is the lack of relative accuracy in theory and relative simplicity in the use of norms guiding the actual work. In fact, the damage occurring to envelope structures in long-span spatial structures, due to wind loads, have been commonplace, which roots in the inadequate understanding of wind load characteristics.In view of this, the paper reformed the shape of the envelope structure of the single spherical shell, which is introduced as the prototype structure, in order to explore a simple and effective method to improve the surface static wind pressure (SSWP) distribution and deformation distribution of the envelope structure in long-span spatial structures.This article has mainly carried on the following work:1. The finite element software ANSYS-CFX has been employed to carry out the SSWP calculation via FSI, in which buildings with simple and regular shape have been introduced as the target for wind loads to carry out the wind field simulation and by which the credibility of the calculation method used in the paper has been evaluated. The comparison of the simulation results with the wind tunnel test results under similar conditions indicates that the boundary conditions set in this simulation model are reasonable and that ANSYS-CFX simulation results are reliable;2. The wind field simulation has been carried out, in which a rib-ring spherical shell surface has been employed as one of the boundaries of the wind field. A preliminary study of the influence on wind velocity and SSWP distribution has been practiced via altering the very boundary of the wind field, which is achieved by means of changing the geometric shape of envelope structure in shell. The results show that oblique-rib type and rib-type transformations are effective.3. The rib-type transformation is applied to Schwedler single-layer spherical shell, the oblique-rib to Kiewitt (K6) single-layer spherical shell, via which the discussion of the SSWP distribution has been implemented. Frame structure of the two shells has been calculated and analyzed respectively on base of the best of the reforming programs and the influence on safety of each frame structure owing to the reforming programs has been evaluated as well.The result indicates that remodeling-program can decrease the area of SSWP- danger-zone considerably on condition that the modeling parameters are suited. This method is also instructive for studying on the improvement of SSWP distribution in other structures.