Reliability Analysis Of The Scaffolding Platform Of The LNG Cargo Containment System Under The Limit State

The scaffolding platform of the LNG cargo containment system is the lightweight scaffold which is used to support the installation engineering of the CCS. Despite the platform is of great quality, requirements for accuracy of this platform is very high.At present, the independent research and development work of the platform is still at its early stages. Its security issue cannot be guaranteed right now since the related products haven’t yet validated by scientific. Therefore, the reliability assessment of the Scaffolding platform is of great significance.This paper takes the 174 000m3 LNG carrier as the object of study. Analyzed the reliability of this structural from the perspective both of linear and non-linear by using the finite element analysis software. The contents are as follows:(1) Established the 3D finite element model of the scaffolding platform in the conditions of linear static, and then take the thought of structure system reliability based on functional requirement. After set the conditions for random variation of input variables, then calculate the structure’s reliability by using both of the Monte Carlo simulation method and the response surface method;(2) In the calculation of static about nonlinear aspects, take fully consideration of the influencing factors of the initial imperfection and the non-linearity of geometrical and material. And then carry out the analysis on the ultimate bearing capacity of the scaffolding platform. First of all, predict the buckling load of the upper limit through the eigenvalue buckling analysis, then track the failure mode of structure system, by using the elements with birth and death capability in ANSYS, in order to exclude the secondary component failure impact on the overall limit bearing capacity calculation. Draw out the load-displacement curve at last to determine the ultimate bearing capacity of structure system;(3) Think of some way to combine the nonlinear finite element analysis method and the response surface method. Using the CCD method to determine the undetermined coefficient through regression analysis, then get the limit state equation according to the principles of response surface method, finally get the reliability index.