The Research On Dynamical Characteristic And Wind-induced Responds Of Spherical Reticulated Mega-structure

For the development of space structure to super long span, applying the concept of reticulated mega-structure to conventional spherical reticulated structures, a new structure is put forward in this paper which is spherical reticulated mega-structure. The rib-ring spherical reticulated mega-structure is researched on structural forms, dynamical characteristic, wind-induced response.At first, the geometrical connections of the main structure of spherical reticulated mega-structure are analyzed and corresponding control parameters are brought forward. The style of sub-structures and the connections of sub-structures with the main structure are analyzed. Automatic configuration is described and a program is developed for creating the structure automatically under AutoCAD with Visual C++. Some necessary fore treatment programs are developed for time-history analysis to wind-induced dynamic response of reticulated structure and an interface program to ANSYS is developed. Support styles of the main structure are also discussed. The work will provide fore treatment for the comprehensive and systemic research on mechanical performance of the structure.The characteristic of wind load is researched, including mean wind speed cross section, the relation between mean wind speed and mean wind pressure, the spectrum characteristic and spatial coherence function of pulsating wind. Quasi-steady assumption is used for translate pulsating wind speed to pulsating wind pressure. Based on the principle of linear auto-regressive model (AR model) by Iwatani, the space and time correlative wind speed time-history simulation program for spatial structures is composed under Matlab. The methods of how to solve correlation function under Matlab and access parameters of AR model are presented. Spectrum analysis of simulated wind speed time-history records show the program is very suitable for the space and time correlative wind speed time-history simulation. The dynamic characteristic and wind-induced vibration analysis theories are studied retrospectively, including subspace iteration method, time-history analysis method and stationary random vibration method of multiple-degree-of-freedom linear System with Rayleigh damping. According stationary random vibration method, the response statistical characteristics of the spherical reticulated mega-structure are obtained.The characteristics of natural vibration frequency of spherical reticulated mega-structure are researched on condition of whether considering the load-bearing contribution of sub-structure or not. A series of parameter analysis are carried out for the alteration regularity of natural vibration frequency of the structure.The static response characteristics of spherical reticulated mega-structure under mean wind load are researched. Numeric certification according stationary random vibration method is carried out for spherical reticulated mega-structure. The definition of internal force gust response factor and displacement gust response factor are discussed and control gust response factor is presented for project estimation. The basic characteristics of the two kinds of gust response factors on spherical reticulated mega-structure under wind load are researched, and a series of parameter analysis are carried out for the alteration regularity of gust response factors of the structure. The value of control gust response factor is supplied for the estimation of spherical reticulated mega-structure.