Study On Wind Pressure Properties And Interpolation Of Roof Structures And Its Wind-Induced Vibration Caculation

In recent years, with the rapid development of China's economy, the growth of people's activities in sports, exhibition and entertainment and the great progresses in new technologies and new materials, the requirement of the long-span spatial structures has reached to an unprecedented extent. As a significant progress in civil engineering, the long-span spatial structure makes itself extraordinarily excellent by adopting graceful structure forms, flexible spatial arrangement and well structural performance, which is very different from traditional structures and receives much public appreciation. However, some disadvantages of long-span spatial structures such as weak stiffness, complicated shape and closely spaced frequencies make long-span spatial structures sensitive to wind load. Wind load is always one of the main loads in structural design and is even more important than seismic load in most cases. In this thesis, there are following main aspects involved:1. Based on wind tunnel tests of three practical projects, this thesis present analyzes and introductions of the characters of wind load in aspects of average wind and fluctuating wind. Programs are made to calculate wind pressure spectra of fluctuating wind and spatial coherency function. And the features and spatial coherency of fluctuating wind self-spectra are summarized. The fluctuating wind pressure self-spectra of quasi-steady method and self-spectra actually measured are compared. The self-spectra of fluctuating wind actually measured is preliminarily fitted by numerical method.2. This thesis interpolates the average wind pressure coefficient by interpolation method of three dimensional surfaces, so average wind pressure interpolation of spatial structure is solved. At the same time, in order to use the time-history analysis to calculate the wind vibration of structure, this thesis makes interpolation calculation to the wind time interval message using the way of three dimensions surface interpolation, which solves the interpolation of fluctuating wind pressure on spatial surface roof structure. Moreover, considering the convenience for the wind vibration response calculation to the frequency-domain analysis method in the non-steady conditon, this thesis makes the frequency-domain analysis to the wind time-history interpolation result.3. This thesis presents the fundamental theory of calculating the wind vibration response by using frequency-domain analysis, and calculates the wind vibration response of a practical project and analyzes the wind vibration features of this project. In addition, some calculation comparisons are given in the selection of the modal numbers in frequency-domain analysis, the influence of spatial coherent function, the effect of modal damping ratio and the cross terms of all computing modals.This thesis introduces the implement process of the wind vibration frequency-domain calculation method by illustrating the calculation in a practical project, which can offer some references to designers in engineering.