Study On Reliability Of Crane Girder Based On Response Surface Method

In practical engineering structure, there are a lot of statically indeterminate structures. When analyzing the structural system reliability,there will be existed large amounts of failure mode. And in practical engineering structure, the function of the structure without explicit expression,and it will cause very unconventional for analyzing the structural system reliability.The failure path of large complex steel structure systems for lattice jib cranes is investigated in this paper. Considering the lack of an explicit function expression in the study of reliability, a method based on a modified response surface method is proposed to quantify the reliability index and the failure probability, capitalizing on the linear- approximated iteration and the difference approach rather than the differential approach in solving nonlinear equations.Based on the improved response surface method, the reliability index is calculated by C# programming; And for the connection of ANSYS with C#; The introduction of MATLAB, is used to determine the lattice boom system stiffness matrix is singular, so as to determine whether the system failure.The major failure path is determined through the analysis of the multiple failure probabilities. The main failure mode of lattice jib cranes is a failure in stability, not a failure in strength based on a comparison of the failure probabilities of both stability failures and strength failures. And the failure path is substantially a rearrangement of the hazardous components and the failure path of components with similar probabilities and close locations varies only in that these components break at distinct starting positions.A proposal is put forward to heighten in engineer practices the security reserves of hazardous components to achieve high reliability of an overall system.