Research On Failure Mechanism Of Single-Layer Spherical Shells With Supporting Structure Subjected To Severe Earthquake

With the advantages of reasonable mechanics,big span and gracefulsculpt, spherical shells which are one of the main forms of the space structureare widely applied in such cases as gymnasiums, departure halls of airport,and Convention and Exhibition Centers, etc. Bearing capacity of sphericalshells is often controlled by stability. Destruction is similar to fragilityfracture and causes enormous casualties and economic losses while losingstability. Accordingly, the stability of single-layer spherical shells hasbecoming important research subjects. Additionally, the application of shellsis based on the cognition to dynamic responses. Therefore, the researchsubject of non-linear stability to shell structure under earthquake action isurgently to be solved and have very important meanings.The dynamic responses, deformation and failure mechanis of 40m-span'sand with f/1 of 1/3's single-layer spherical shells with supporting structure areinvestigated under earthquake action by the finite element program ANSYS inthe paper. In the studying, both the geometric and the material non-linearityhave been taken into consideration.First of all, the dynamic responses of single-layer spherical shellsbetween supporting structure included and excluded are discussed under thethree-oriented action of El-centro earthquake. Accordingly, Comparations between bending deformation of the bars included and excluded arediscussed.Then, the dynamic responses of single-layer spherical shells arethoroughly investigated under the three-oriented action of El-centroearthquake. The characteristics responses of structure such as keypointdisplacement on spherical shells, Plastic inner forcere distribution, plasticelement ratio of shells, plastic deformation of elements, force and moment ofelement and energy, etc are written down in pace with seismic inputacceleration. Simultaneously, the variation of the dynamic response accordingto the increase of acceleration is investigated.Finally, the effects of various primary parameters are carried out ondynamic stability of single-layer spherical shells including seismic wave, therise-to-span ratio, cross-sectional areas of members, damping and initialimperfectiong. The result as follows: 1) the critical load of single-layerspherical shells differs greatly under different seismic wave. 2) Therise-to-span ratio influence remarkably the stability of single-layer sphericalshells.With rise-to-span ratio's aggrandizement, the critical load of thesingle-layer spherical shells reduces gradually. 3) When cross-sectional areasof members are increased, the stiffness of the single-layer spherical shellsheightens and the critical load enhance.4) Due to the existence of the damping,the critical load of the single-layer spherical shell of improves remarkably.Thus, damping exerts a beneficial influence to stablity of single-layerspherical shells. 5) Considering the initial imperfection, generally adverselyaffect stability of the structure under earthquake action.