Buckling Analysis And The Seismic Inspirit Influence On Stiffened Cylindric Warehouse

Stiffened cylindric warehouses offer the most efficient usage of structural material in many fields. They are widely used in aircraft, space rockets, motor vehicles, nuclear containment vessel, submarines, domestic food and drink containers, cooling towers, silos, tanks, pipelines etc. The failures of this kind of structures often occur which demonstrate that there still many problems existed in current researches. This paper is about the structure analysis of a storage project concerning 8000 ton Aluminum-Magnesium powder, which is supported by the Guiyang Academy of Aluminum and Magnesium. The objective of this dissertation is to analyze the nonlinear buckling of the stiffened cylindric warehouse under the action of unsymmetrical axis compression, lateral pressure and seismic inspirit , respectively. A set of new exact finite element formulations is developed for the nonlinear collapse analysis of elastic curved segmented and branched stiffened cylindric warehouse. A useful theoretical finite element model for the analysis of stiffened cylindric warehouse is set up, which becomes a useful tool for engineering designs and researches. The main contents are as follows: To begin with, the geometric nonlinear and material nonlinear buckling stress-strain relations for stiffened cylindric warehouse of general forms are established. The mainly difference between these relations and previous works is the recognition that nonlinear strains arising from products of in-plain strain terms may be important. The initial geometric perfections are also been included into the relations. The numerical results show that the nonlinear buckling from different kinds of pressures play an important role and can not be neglected in practical engineering. Secondly, by deducing the buckling equation of the fixed-free constant-thickness stiffened cylindric warehouse, the theoretic results are obtained. At the same time, the finite element analysis theory of stiffened cylindric warehouse under the action of unsymmetrical loading is developed. The two methods are matched. The elastic and plastoelastic large deflections theory can be used to trace whole equilibrium path, describe the buckling deflections and calculate the forces of the structure. In this theory the material plasticity is introduced to consider the true structure behavior. The numerical results show that the loading capacity of stiffened cylindric warehouse is mainly affected by the geometric nonlinearity and material nonlinearity. Finally, deflection simulation in dynamic analysis of stiffened cylindric warehouse under asynchronous exciting wave, that is traveling wave, is demonstrated. Based on depicting traveling wave with multi-point sine wave with different-phase, combining with Tianjin a certain degree earthquake, we imitate the traveling wave effect with inputting the path-difference lagging behind seismic inspirit and different direction of the wave. It is showed that seismic wave, especially the wave effect on path-difference lagging behind seismic inspirit has important influence on the structure. It is also a problem which must be confronted with in the project application.