The Study On Wind-pressure Field Reconstruction And Wind-induced Response Of Long-span Roof Structure

With the development of social economy and the progress of civilization,people's aesthetic and functional requirements of buildings have been upgraded.Due to the characteristics of various forms and large internal space capacity,long-span roof structures have been widely used in the field of engineering construction.Because of their light weight,small rigidity and dense frequency of vibration,such structures are very sensitive to wind loads.The design department needs to carry out the design of structural wind resistance specially.Based on the rigid model wind tunnel test of the long-span roof of an airport terminal,the following detailed research work is carried out on the reconstruction of wind pressure field,the prediction of wind pressure of unknown position,the fast and effective calculation of wind-induced vibration response,and the effect of damping ratio on wind-induced response:(1)From the perspective of history and structure form,the development of long-span roof structure is summarized and the hazards caused by wind are described.Aiming at the problem of sparse layout of pressure measuring points in wind tunnel test and complex resonant function of long-span roof structure,the main content of the research is presented in this paper.(2)Proper Orthogonal Decomposition method is deduced through the extremum principle of space projection,which is used to reconstruct stochastic wind pressure field.It is proposed that the eigenvalue is used to characterize how much energy is contained in the eigen modal.Under the premise of not changing the eigenvalue of the matrix,the arrangement of uneven pressure measuring points is handled by clever contract transformation and similarity transformation.This paper deduces the basic principle of Kriging method,and introduces the optional regression model and the correlative function model.(3)Complete Quadratic Combination method,Square Root Sum of Square method,Pseudo Excitation Method and Harmonic Excitation Method are deduced in detail.And the characteristics of these four kinds of wind-induced vibration responses calculation methods based on frequency domain are compared.(4)A rigid model wind tunnel test for an airport terminal is carried out,and the test process is described in detail,including the work of model fabrication,the layout of measuring points,atmospheric boundary layer simulation and data processing.(5)The wind pressure field on the surface of the long-span roof structure is reconstructed by using the data obtained from the wind tunnel test.The reconstruction effect of different regions is evaluated,and the wind pressure of the non-arranged surveying points is predicted by the reconstructed pressure field with five different correlative function models.The prediction results are analyzed,and the suitable correlative function model are given for each region.(6)The finite element model of the roof structure of the corridor is established,and the modal analysis is carried out.Wind-induced vibration response analysis of the structure was carried out by using the reconstructed wind loads,and the applicability of CQC,PEM,and HEM was verified.The effect of damping ratio on wind-induced response and the feasibility of calculation equivalent static wind loads using displacement wind vibration coefficient are studied.