Study On Static And Dynamic Perormance Of The Double Table-Flap Latticed Shell Structure

The table-flap latticed shell is a new type of structure developped in recent years, which is made by flat shell elements according to certain rules. It is rich in structural style and has many advantages in mechanical characteristics. So far,there are not many papers disscusing this structure throughout the world. In this thesis its characteristic under static loads and dynamic loads was analyzed systematically on the base of the projcet of the Nan yang jade supermarket.The double table-flap latticed shell structure is used through the roof of the selection of the pyramid steel were discussed, and some key problems are dwelled on in this paper. By the geometrical nonlinear finite element method, the nonlinear stability analysis is carried out. By Considering the geometrical and the physical nonlinear, the whole structural buckling process and the limited carrying capacity is analyzed. The influence of spring support to the stability of the structure is analyzed. The calculated results indicate that the double layer table-flap shell is fit to apply in the pyramid big roof structure. It has the reasonable performances and the economical technical parameters, and it may provide reference for similar projects.There are three geometrical imperfection analysis methods on overall stability of latticed shell structures,but the worst imperfection has not been determined. The modal analysis of the ideal strucure was carried out firstly. The deformation of each buckling mode of the structure was introduced as initial imperfection,and the nonlinear stability analysis of the strutcure was carried out to find out which is the worst buckling mode. Then, the worst buckling mode was compared with the static buckling mode which was proposed by Bault to find out which imperfection mode are even more harmful. The calculated results indicate that the initial deformation of the first buckling mode and the static buckling mode are all not the worst mode. The ninth buckling mode is worse than them.Then, vibration character of the double table-flap latticed shell structure was discussed, and their first 10 vibration modes are analyzed in detail.The influence on vibration characteristic acted by different parameters including rise-to-span ratio, shell thickness, load,section area, constraint condition, temperature and the materials physical nonlinear was studied, and some useful conclusions were obtained for practical engineering.Finally, vibration shapes-separation-spectra-method and time-history method were adopted to analyze the dynamic response of the double table-flap latticed shell structure under common earthquake. By comparing dynamic response in different dimension seismic excitation, the value and distribution of dynamic internal force were obtained. In addition, the results from vibration shapes-separation-spectra method and time-history method were compared, and the reasons was analyzed. The compared result is valuable for aseismatic design.